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Inside this large, glass box, | 0:00:25 | 0:00:28 | |
something extraordinary is happening. | 0:00:28 | 0:00:32 | |
Food is being left to rot for eight weeks | 0:00:32 | 0:00:35 | |
in our own unique laboratory. | 0:00:35 | 0:00:37 | |
This is an investigation | 0:00:39 | 0:00:42 | |
into nature's biggest and best recycler... | 0:00:42 | 0:00:47 | |
..decay. | 0:00:47 | 0:00:49 | |
And it's being done on a scale that has never been tried before. | 0:00:49 | 0:00:54 | |
I'm Dr George McGavin. I'm a biologist with a particular passion for insects. | 0:00:54 | 0:00:59 | |
The Rot Box detectives, Iona, Rosie, | 0:00:59 | 0:01:04 | |
Ruaridh, Mram and Jamie | 0:01:04 | 0:01:07 | |
are going to help me investigate the amazing world of rot and decay. | 0:01:07 | 0:01:13 | |
'There's bacteria...' | 0:01:17 | 0:01:19 | |
MACHINE BLEEPING | 0:01:19 | 0:01:20 | |
Look at that. That really is smelly. | 0:01:20 | 0:01:23 | |
'..flies...' | 0:01:23 | 0:01:24 | |
I want to show you the fish. It's been completely eaten out. | 0:01:24 | 0:01:27 | |
'..and mould.' | 0:01:27 | 0:01:29 | |
20 or 30 species of fungus?! | 0:01:29 | 0:01:32 | |
At Rot Box Detective HQ, I'm meeting up with the team. | 0:01:35 | 0:01:40 | |
-Hi, team. -ALL: Hi. -How do you think we made the Rot Box? | 0:01:40 | 0:01:44 | |
-Great difficulty. -Yeah, it was quite difficult actually. | 0:01:44 | 0:01:47 | |
We wanted to make a typical kitchen and garden | 0:01:47 | 0:01:51 | |
and fill it full of the sort of food you'd have | 0:01:51 | 0:01:54 | |
if you were having a party. | 0:01:54 | 0:01:56 | |
We wanted it quite warm, as if it was a hot summer's day | 0:01:56 | 0:01:59 | |
and we wanted quite humid as well. | 0:01:59 | 0:02:01 | |
So why do you think we did that? | 0:02:01 | 0:02:04 | |
The bacteria would come | 0:02:04 | 0:02:06 | |
because the hotter it is, like if you left a drink out | 0:02:06 | 0:02:10 | |
for ages, it would go all warm and horrible. | 0:02:10 | 0:02:13 | |
Exactly. The hotter it is, the faster things happen. | 0:02:13 | 0:02:17 | |
-All organisms need some form of...? -Water. -Water, yes. Exactly. | 0:02:17 | 0:02:22 | |
So the best conditions for bacteria and fungi | 0:02:22 | 0:02:26 | |
are hot and sweaty, basically. | 0:02:26 | 0:02:28 | |
The hotter it is, the faster things rot. | 0:02:28 | 0:02:30 | |
This giant Rot Box has taken a team of engineers | 0:02:30 | 0:02:35 | |
and scientists eight months to design and build. | 0:02:35 | 0:02:39 | |
Conditions inside are now perfect for rot to begin. | 0:02:39 | 0:02:42 | |
It's hot, humid and there's plenty of air | 0:02:45 | 0:02:48 | |
so it doesn't take long for the mould to take hold | 0:02:48 | 0:02:52 | |
and begin breaking down the food. | 0:02:52 | 0:02:54 | |
By only the second day, there are dramatic changes inside. | 0:02:56 | 0:03:00 | |
'It's really warm in here,' | 0:03:00 | 0:03:04 | |
it's 25 degrees. That's like a warm summer day, | 0:03:04 | 0:03:06 | |
so some things are drying out | 0:03:06 | 0:03:08 | |
the chilli con carne is already growing a layer of mould. | 0:03:08 | 0:03:12 | |
That shows there are fungal spores drifting around in the atmosphere | 0:03:12 | 0:03:16 | |
and settling on food. Over here, the sandwiches | 0:03:16 | 0:03:20 | |
which originally filled the box, | 0:03:20 | 0:03:23 | |
up to the top, have sagged down to about half their height. | 0:03:23 | 0:03:26 | |
-I think it's a fish. -I thought that was the fish. | 0:03:26 | 0:03:30 | |
There's two fishes. | 0:03:30 | 0:03:32 | |
-Eurgh, what's that? -Oh! -Where was it? | 0:03:32 | 0:03:36 | |
-There. It's a dead mouse. -Eurgh! | 0:03:36 | 0:03:39 | |
Disgusting! | 0:03:39 | 0:03:40 | |
The Rot Box Detectives are intrigued and excited by what they see. | 0:03:40 | 0:03:44 | |
It's time for them to start their own investigations. | 0:03:44 | 0:03:49 | |
Who knows what an experiment is? | 0:03:49 | 0:03:52 | |
It's an experiment when you judge something by something else | 0:03:52 | 0:03:56 | |
and you see the difference maybe. | 0:03:56 | 0:03:58 | |
Yeah, pretty close. | 0:03:58 | 0:04:00 | |
If you have a question and you want to find the answer. | 0:04:00 | 0:04:03 | |
Exactly. It's a controlled test that helps you to see | 0:04:03 | 0:04:08 | |
if a question you ask is correct or not. | 0:04:08 | 0:04:11 | |
So how would you design an experiment to investigate | 0:04:11 | 0:04:14 | |
the effect of temperature on how fast things rot? | 0:04:14 | 0:04:16 | |
Heat and cold. | 0:04:16 | 0:04:18 | |
OK, so we have one hot environment and one cold one, | 0:04:18 | 0:04:21 | |
which is a fridge and the airing cupboard. That's our variable. | 0:04:21 | 0:04:25 | |
So what will we have to put in those two environments? | 0:04:25 | 0:04:28 | |
-Something that will... -Rot. | 0:04:28 | 0:04:30 | |
Yes! Something that will rot. | 0:04:30 | 0:04:33 | |
So what sort of things do you think are going to rot easily? | 0:04:33 | 0:04:37 | |
-Fruit and bread. -Fruit and bread, yeah. | 0:04:37 | 0:04:41 | |
-Which do you think would grow the most mould? -I would say the bread. | 0:04:41 | 0:04:46 | |
-Yeah. -Apples. -Apples, OK. | 0:04:46 | 0:04:47 | |
Peppers, because in the Rot Box they were all really black and crispy. | 0:04:47 | 0:04:52 | |
OK, so you've got all these things. What are you going to put them in? | 0:04:52 | 0:04:56 | |
-Do you think you could put them in a glass box. -Yeah, OK. | 0:04:56 | 0:04:59 | |
So you can each have two boxes, one will go in the fridge, | 0:04:59 | 0:05:03 | |
the other in the airing cupboard where it's warm. | 0:05:03 | 0:05:06 | |
We've got one variable, which is if it's hot or cold. | 0:05:06 | 0:05:09 | |
-Everything else should be the same. Why? -Because it's a fair test. | 0:05:09 | 0:05:13 | |
Absolutely. It has to be a fair test. | 0:05:13 | 0:05:15 | |
If you don't have the same things, it's not fair. | 0:05:15 | 0:05:18 | |
-How does bacteria get into it? -Good question. | 0:05:18 | 0:05:22 | |
Well, bacteria is everywhere in the environment. | 0:05:22 | 0:05:24 | |
We have bacteria all over our hands, even after you've washed them. | 0:05:24 | 0:05:28 | |
There's bacteria all over this box, | 0:05:28 | 0:05:30 | |
so the bacteria and the fungi are there, | 0:05:30 | 0:05:33 | |
we just encourage them to grow. | 0:05:33 | 0:05:35 | |
Our big Rot Box is also full of bacteria. | 0:05:36 | 0:05:40 | |
In a matter of hours, they have started to do their work. | 0:05:40 | 0:05:45 | |
The clearest signs of change are on the chicken. | 0:05:45 | 0:05:48 | |
In just one day, our time lapse cameras | 0:05:48 | 0:05:50 | |
show these blotches appearing on its skin, | 0:05:50 | 0:05:54 | |
I've asked Dr Clare Taylor, a microbiologist, to join me | 0:05:59 | 0:06:03 | |
and explain what's happening. | 0:06:03 | 0:06:05 | |
Well, Clare, that chicken is beginning to look | 0:06:11 | 0:06:13 | |
pretty discoloured. | 0:06:13 | 0:06:15 | |
It smells a bit as well. | 0:06:15 | 0:06:16 | |
There's beginning to be a slight whiff. What have you got on this? | 0:06:16 | 0:06:19 | |
I tell you what I've got a UV light | 0:06:19 | 0:06:22 | |
so we can take a look more closely at the surface. | 0:06:22 | 0:06:25 | |
-Now you can't see it. -No, can't see anything. | 0:06:25 | 0:06:28 | |
Take a look at that! | 0:06:28 | 0:06:29 | |
It's glowing! So all these areas are glowing sort of blue. | 0:06:29 | 0:06:34 | |
Exactly, so where you can see those glowing bits, that's bacteria. | 0:06:34 | 0:06:40 | |
So even though we can't see them, bacteria are everywhere. | 0:06:41 | 0:06:45 | |
They're all around us. | 0:06:45 | 0:06:47 | |
'Now the team and I are going to make our own mini Rot Boxes.' | 0:06:49 | 0:06:53 | |
LAUGHTER | 0:06:53 | 0:06:56 | |
Right, two each. Pass them down. | 0:06:56 | 0:06:59 | |
Two for you, two for you. | 0:06:59 | 0:07:02 | |
Right, you can put whatever you want in the box, | 0:07:02 | 0:07:06 | |
as long as both boxes are exactly the same. | 0:07:06 | 0:07:11 | |
I thought it might be interesting to have one inanimate object, | 0:07:11 | 0:07:14 | |
like a bolt or something. | 0:07:14 | 0:07:17 | |
-Will that rot? -No. -Why won't it rot? -Because it's a metal object. | 0:07:17 | 0:07:21 | |
It's metal, yeah, It isn't alive, is it? | 0:07:21 | 0:07:24 | |
Fill your boxes! | 0:07:26 | 0:07:27 | |
So in order for it to be properly scientific, | 0:07:44 | 0:07:48 | |
we need to write down our names on a piece of paper, the date, | 0:07:48 | 0:07:51 | |
and describe what we did. | 0:07:51 | 0:07:53 | |
We have to say what the experiment was supposed to do, | 0:07:53 | 0:07:55 | |
and what our predictions for the outcome of the experiment is. | 0:07:55 | 0:07:59 | |
When we take our boxes out of the refrigerator | 0:07:59 | 0:08:02 | |
and the airing cupboard, we then write down our results, OK? | 0:08:02 | 0:08:05 | |
'I think the metal thing might get rusty, | 0:08:05 | 0:08:08 | |
'because when I see the railings they mostly get brown from silver. | 0:08:08 | 0:08:13 | |
'So I think it might rust a little. | 0:08:13 | 0:08:16 | |
'I think there will be less mould in the cold one. | 0:08:16 | 0:08:19 | |
'It might have a little bit of bacteria and a little bit of mould. | 0:08:19 | 0:08:22 | |
'I think the pepper will rot the most, because when we went to see | 0:08:22 | 0:08:27 | |
'the Rot Box, in the fruit bowl, the peppers were absolutely disgusting. | 0:08:27 | 0:08:31 | |
'I don't think that the paper will go mouldy, but I think some | 0:08:31 | 0:08:35 | |
'of the mould from the apple would probably go a bit onto the paper. | 0:08:35 | 0:08:39 | |
'I think the potatoes will rot the quickest.' | 0:08:39 | 0:08:44 | |
-I'm quite excited about this. -Me too, yeah. | 0:08:44 | 0:08:48 | |
It'll be really good, this experiment. Really interesting. | 0:08:48 | 0:08:52 | |
We might even find some undescribed species of fungi or bacteria. | 0:08:52 | 0:08:56 | |
Who knows? It could happen. | 0:08:56 | 0:08:59 | |
Back at the big Rot Box, | 0:08:59 | 0:09:01 | |
the Detectives continue to be amazed by the world of decay. | 0:09:01 | 0:09:04 | |
But will they see similar results in their mini Rot Boxes? | 0:09:06 | 0:09:10 | |
Their experiment tests how temperature affects | 0:09:10 | 0:09:15 | |
the speed of rot. They filled two boxes | 0:09:15 | 0:09:18 | |
with exactly the same foods. The only variable is temperature. | 0:09:18 | 0:09:22 | |
One box is in a hot place and one box is in a cold place. | 0:09:22 | 0:09:27 | |
It's a fair test. | 0:09:27 | 0:09:29 | |
They've recorded what they did, how they did it | 0:09:29 | 0:09:32 | |
and what they think might happen. | 0:09:32 | 0:09:35 | |
What will the detectives discover? | 0:09:35 | 0:09:37 | |
Inside this large, glass box, | 0:09:44 | 0:09:47 | |
something extraordinary is happening. | 0:09:47 | 0:09:52 | |
Food is being left to rot for eight weeks | 0:09:52 | 0:09:54 | |
in our own unique laboratory | 0:09:54 | 0:09:56 | |
This is an investigation | 0:09:59 | 0:10:01 | |
into nature's biggest and best recycler... | 0:10:01 | 0:10:05 | |
..decay. | 0:10:06 | 0:10:08 | |
And it's being done on a scale that has never been tried before. | 0:10:08 | 0:10:12 | |
I'm Dr George McGavin. I'm a biologist with a particular passion for insects. | 0:10:13 | 0:10:19 | |
The Rot Box detectives, Iona, Rosie, | 0:10:19 | 0:10:23 | |
Ruaridh, Mram and Jamie | 0:10:23 | 0:10:26 | |
are going to help me investigate the amazing world of rot and decay. | 0:10:26 | 0:10:31 | |
'There are flies...' | 0:10:33 | 0:10:37 | |
Well, there are simply too many flies in here. | 0:10:37 | 0:10:40 | |
It's becoming quite unpleasant. | 0:10:40 | 0:10:43 | |
'..bacteria...' | 0:10:43 | 0:10:46 | |
-Oho! -Take a look at that. -It's glowing! | 0:10:46 | 0:10:48 | |
'..and mould.' | 0:10:48 | 0:10:50 | |
Even the hamburgers are wrapped up and they're covered in mould. Ooh! | 0:10:50 | 0:10:54 | |
That might blow at any time. | 0:10:54 | 0:10:56 | |
Pass them down. Two for you... | 0:11:00 | 0:11:02 | |
'Four weeks ago, the Rot Box Detectives built their own | 0:11:02 | 0:11:05 | |
'mini Rot Boxes so they could examine rot | 0:11:05 | 0:11:08 | |
'more closely for themselves.' | 0:11:08 | 0:11:12 | |
They wanted to see how temperature affects the speed of rot, | 0:11:13 | 0:11:18 | |
so they designed a test, an experiment to find the answer. | 0:11:18 | 0:11:21 | |
They had two boxes each and filled each box with the same things. | 0:11:24 | 0:11:30 | |
To make the test fair, | 0:11:30 | 0:11:33 | |
everything was the same except for one variable, which was temperature. | 0:11:33 | 0:11:38 | |
They wrote down their hypothesis, what they thought would happen. | 0:11:40 | 0:11:46 | |
I think there'll be less mould in the cold one than the hot one. | 0:11:46 | 0:11:50 | |
It might have a little bit of bacteria. | 0:11:50 | 0:11:52 | |
'Scientists often work in laboratories, | 0:11:57 | 0:12:01 | |
'so we've come along to one to examine the results | 0:12:01 | 0:12:04 | |
'of our four-week-old Rot Boxes.' | 0:12:04 | 0:12:06 | |
I want you to meet a friend of mine called Patrick, who's a mycologist. | 0:12:08 | 0:12:13 | |
That's an expert on fungi. | 0:12:13 | 0:12:15 | |
Now we can only open the boxes because we're in a lab | 0:12:15 | 0:12:18 | |
and because Patrick here is a specialist in fungi. | 0:12:18 | 0:12:22 | |
He will tell us if there's anything harmful to us in these boxes. | 0:12:22 | 0:12:26 | |
-I suspect there isn't anything that's that harmful. -It's unlikely. | 0:12:26 | 0:12:30 | |
As long as we don't sniff or inhale them or eat them, touch them | 0:12:30 | 0:12:34 | |
and put our fingers in our mouths, we should be fine. | 0:12:34 | 0:12:37 | |
I know it's going to be very hard for you to resist, | 0:12:37 | 0:12:41 | |
with your fingers touching things, | 0:12:41 | 0:12:43 | |
so I think we should all put on gloves. | 0:12:43 | 0:12:46 | |
OK, let's open the cold box first. So this is Ruaridh's one. | 0:12:53 | 0:12:57 | |
Well, I can see there is a little bit of mould on the bread there. | 0:12:57 | 0:13:01 | |
Penicillin probably. | 0:13:01 | 0:13:02 | |
But everything looks as it would do when it's been fairly freshly made. | 0:13:02 | 0:13:07 | |
None of it's gone mushy or soggy. | 0:13:07 | 0:13:09 | |
We'll open the one that's been in the warm temperature. | 0:13:09 | 0:13:12 | |
-Ooh! -CHILDREN: Eurgh! | 0:13:12 | 0:13:15 | |
-That's very different, isn't it? -The bread has completely gone down | 0:13:15 | 0:13:19 | |
to a kind of soggy mess. | 0:13:19 | 0:13:21 | |
The apple looks like it's been poached or something. | 0:13:21 | 0:13:24 | |
Ruaridh, you've at least shown what you thought was going to happen. | 0:13:24 | 0:13:29 | |
There's more fungus growing in your hot box, but you were right | 0:13:29 | 0:13:32 | |
about there being a little bit of fungus in your cold one. | 0:13:32 | 0:13:35 | |
So this is Jamie's box. | 0:13:35 | 0:13:38 | |
-Was the bread already this size? -I don't think it was. | 0:13:38 | 0:13:42 | |
I think it's shrunken down. | 0:13:42 | 0:13:43 | |
Why are the bananas pushed in? | 0:13:43 | 0:13:46 | |
The fungus has taken the moisture out of the banana | 0:13:46 | 0:13:49 | |
and used it for itself. It's shrunken right down. | 0:13:49 | 0:13:52 | |
The fungi on my mushroom looks different than the other ones. | 0:13:52 | 0:13:56 | |
OK, so we have a comparison. | 0:13:56 | 0:13:58 | |
Fungi often changes depending on what part in their life cycle. | 0:13:58 | 0:14:03 | |
Sometimes they can change colour in a few days. | 0:14:03 | 0:14:06 | |
That one's plain white and that one's really bubbly. | 0:14:06 | 0:14:10 | |
-Is that hard or soft, the mould on there? -Really soft. | 0:14:10 | 0:14:14 | |
-It's breaking down. -Looks like a marshmallow. | 0:14:14 | 0:14:16 | |
It is just like a marshmallow actually. | 0:14:16 | 0:14:19 | |
That's the fungal mould that's growing through there. | 0:14:19 | 0:14:23 | |
Would you say there's anything edible in any of the hot boxes? | 0:14:23 | 0:14:27 | |
Let's have a look and see. | 0:14:27 | 0:14:28 | |
No, it's all soft and horrible. | 0:14:28 | 0:14:32 | |
Because we cut the oranges, | 0:14:32 | 0:14:33 | |
the fungi and bacteria have got inside them and broken them down. | 0:14:33 | 0:14:37 | |
But if you had a whole orange in there, it might not rot down. | 0:14:37 | 0:14:40 | |
But you should still never eat anything in these experiments. | 0:14:40 | 0:14:44 | |
Back at the big Rot Box, | 0:14:45 | 0:14:47 | |
Patrick and I are staggered by what we discover. | 0:14:47 | 0:14:50 | |
Now, this to my, Patrick, | 0:14:52 | 0:14:55 | |
is one of the most amazing things I've ever seen. | 0:14:55 | 0:14:58 | |
Look at it! I mean, that was a pile of cheese | 0:14:58 | 0:15:01 | |
and tomato sandwiches that was up to the top of the box. | 0:15:01 | 0:15:05 | |
-How many actual species of fungus are here? -Oh, at least 20 or 30. | 0:15:05 | 0:15:09 | |
-Maybe more. -20 or 30 species of fungus?! | 0:15:09 | 0:15:12 | |
-Look at that. I mean, it's a solid mat. -Oh, yeah. | 0:15:12 | 0:15:16 | |
There are the layers of sandwich. | 0:15:16 | 0:15:19 | |
It's all the way through, it's completely through. | 0:15:19 | 0:15:22 | |
There aren't many flies here, of course. | 0:15:22 | 0:15:25 | |
Yeah, it was sealed in the box so the flies couldn't get in. | 0:15:25 | 0:15:28 | |
Big contrast there to the fruit bowl which was left open. | 0:15:28 | 0:15:32 | |
A couple of weeks ago, it was really covered in thick layers of fungus. | 0:15:32 | 0:15:37 | |
-Look at the fly. -The flies have stripped it bare. | 0:15:37 | 0:15:40 | |
The flies have gone in there, they've eaten the fungus, | 0:15:40 | 0:15:44 | |
eaten the spores and really just recycling the fungi. | 0:15:44 | 0:15:47 | |
Moulds are masters of decay. | 0:15:47 | 0:15:50 | |
They're a form of fungi, the most versatile | 0:15:50 | 0:15:53 | |
and important decomposers on the planet. | 0:15:53 | 0:15:56 | |
Fungi can grow on almost anything. | 0:15:56 | 0:15:59 | |
In our box, moulds are attacking our fruit and vegetables | 0:15:59 | 0:16:05 | |
and spread by releasing spores into the air which are like seeds. | 0:16:05 | 0:16:10 | |
They find new places to settle and grow, | 0:16:10 | 0:16:12 | |
overwhelming everything in their path, even our meat. | 0:16:12 | 0:16:17 | |
There are up to 500 spores in every cubic metre of air in your home. | 0:16:19 | 0:16:24 | |
But they're so small, you can only see them with a microscope. | 0:16:24 | 0:16:28 | |
Whoa. | 0:16:33 | 0:16:34 | |
It looks like snow. | 0:16:34 | 0:16:37 | |
It looks like the fluff on my teddy bear or something like that. | 0:16:40 | 0:16:44 | |
The white looks like the Antarctic. | 0:16:44 | 0:16:46 | |
Now this microscope only magnifies things about 100 times. | 0:16:49 | 0:16:52 | |
But in the Rot Box, | 0:16:52 | 0:16:54 | |
we had a microscope that could magnify stuff by 7,000 times. | 0:16:54 | 0:16:59 | |
I want you to take a look at some of the fungi we filmed there. | 0:16:59 | 0:17:03 | |
This is the kind of mould you might find in your bread, | 0:17:05 | 0:17:07 | |
magnified by 7,000 times. | 0:17:07 | 0:17:10 | |
The thread-like stalks are ten times finer than a human hair. | 0:17:11 | 0:17:16 | |
The fluffy ball shapes at the top are where the spores live. | 0:17:17 | 0:17:22 | |
Much like dandelion seeds, | 0:17:22 | 0:17:24 | |
the spores are released into the air and carried to new places to grow. | 0:17:24 | 0:17:29 | |
You might not always be able to see it, but mould is everywhere. | 0:17:30 | 0:17:34 | |
Your house alone may contain an unbelievable 1,000 different | 0:17:34 | 0:17:39 | |
types of mould. | 0:17:39 | 0:17:41 | |
Patrick, thanks very much. | 0:17:41 | 0:17:42 | |
It's been a real thrill to be able to use your lab and your expertise. | 0:17:42 | 0:17:47 | |
-I'm sure we've learned quite a lot, haven't we? -Yeah. -So thank you very much. | 0:17:47 | 0:17:50 | |
Back inside the big Rot Box, mould continues to astound and amaze. | 0:17:55 | 0:18:00 | |
The Rot Box Detectives have grown their own fantastic fungi | 0:18:01 | 0:18:04 | |
in their mini Rot Box experiments. | 0:18:04 | 0:18:06 | |
They found that there was more mould in the hot box than the cold box. | 0:18:09 | 0:18:13 | |
This is because mould grows faster in warm conditions | 0:18:15 | 0:18:19 | |
than in cold conditions. | 0:18:19 | 0:18:22 | |
They prove that their hypothesis, | 0:18:22 | 0:18:24 | |
which is what they thought might happen, was correct. | 0:18:24 | 0:18:28 | |
Inside this large, glass box, | 0:18:42 | 0:18:44 | |
something extraordinary is happening. | 0:18:44 | 0:18:48 | |
Food is being left to rot for eight weeks | 0:18:48 | 0:18:51 | |
in our own unique laboratory. | 0:18:51 | 0:18:56 | |
This is an investigation into nature's biggest and best recycler... | 0:18:57 | 0:19:04 | |
decay. | 0:19:04 | 0:19:05 | |
And it's being done on a scale that has never been tried before. | 0:19:05 | 0:19:10 | |
I'm Dr George McGavin. | 0:19:10 | 0:19:12 | |
I'm a biologist with a particular passion for insects. | 0:19:12 | 0:19:16 | |
The Rot Box detectives, Iona, Rosie, Ruaridh, Mram and Jamie | 0:19:16 | 0:19:23 | |
are going to help me investigate the amazing world of rot and decay. | 0:19:23 | 0:19:29 | |
'We'll see flies...' | 0:19:34 | 0:19:36 | |
The burgers that were opened are riddled with maggots. | 0:19:36 | 0:19:40 | |
'..mould...' | 0:19:40 | 0:19:41 | |
It's almost a battle zone in your bread bin. | 0:19:41 | 0:19:45 | |
'..and bacteria.' | 0:19:45 | 0:19:47 | |
I wonder how many bacteria are on that. | 0:19:47 | 0:19:50 | |
At Rot Box Detective HQ, we're investigating some really bad smells. | 0:19:52 | 0:19:57 | |
I've got a challenge for you. | 0:19:57 | 0:19:59 | |
How can you tell if food is safe to eat, if it's off, | 0:19:59 | 0:20:04 | |
without actually tasting it? | 0:20:04 | 0:20:06 | |
Because of the smell? | 0:20:06 | 0:20:07 | |
Smell is a very good clue. | 0:20:07 | 0:20:09 | |
Maybe from its looks, because sometimes you see the bread is white, | 0:20:09 | 0:20:14 | |
and sometimes it's green. So you can spot the difference between them if it's rotten or not. | 0:20:14 | 0:20:21 | |
Mm-hm. If a food smells funny, or off, | 0:20:21 | 0:20:24 | |
or if it looks peculiar, that's a really good warning sign, isn't it? | 0:20:24 | 0:20:29 | |
Well, I've brought some items along for you to smell. See if you think they're off. | 0:20:29 | 0:20:35 | |
Here's the first one. | 0:20:35 | 0:20:36 | |
Cheese. What do you think of that? | 0:20:36 | 0:20:38 | |
-That's all right. -Urgh! | 0:20:38 | 0:20:41 | |
I don't think it's off. | 0:20:41 | 0:20:42 | |
It's strong but I wouldn't say it's off. | 0:20:44 | 0:20:47 | |
It's not off, but it smells really, really strong. | 0:20:47 | 0:20:50 | |
Yeah, it's strong, but it's not a lot to... | 0:20:52 | 0:20:55 | |
Let's try... Now, don't smell this one, OK? | 0:20:55 | 0:20:59 | |
It's mouldy bread, so you don't have to smell it. | 0:20:59 | 0:21:02 | |
Very mouldy, isn't it? | 0:21:02 | 0:21:04 | |
If you found that in your bread bin, | 0:21:06 | 0:21:07 | |
-you wouldn't want to put that in your toaster, would you? -No, | 0:21:07 | 0:21:11 | |
you'd be mad to eat that. | 0:21:11 | 0:21:13 | |
Dark green, yellow... | 0:21:14 | 0:21:17 | |
Yellow in the bottom... | 0:21:17 | 0:21:19 | |
It's mostly green on the top. | 0:21:19 | 0:21:22 | |
Eugh! | 0:21:22 | 0:21:23 | |
It looks like a sponge you use for washing the dishes! | 0:21:23 | 0:21:27 | |
HE LAUGHS | 0:21:27 | 0:21:29 | |
Now, I've got an extra special treat - | 0:21:29 | 0:21:31 | |
I've brought you your lunch. Have a good smell of that. That's fish. | 0:21:31 | 0:21:35 | |
Urgh! | 0:21:35 | 0:21:36 | |
That's disgusting! | 0:21:36 | 0:21:39 | |
Oh! Ho, ho! | 0:21:41 | 0:21:43 | |
HE CHOKES | 0:21:43 | 0:21:44 | |
That is... | 0:21:44 | 0:21:47 | |
Eugh! | 0:21:47 | 0:21:49 | |
THEY LAUGH | 0:21:49 | 0:21:52 | |
Anyone else want an extra smell? | 0:21:52 | 0:21:54 | |
THEY LAUGH AND SHRIEK | 0:21:54 | 0:21:56 | |
The reason this smells SO bad | 0:21:58 | 0:22:00 | |
is it's loaded with bacteria | 0:22:00 | 0:22:02 | |
that have all been developing in there, | 0:22:02 | 0:22:04 | |
and they're producing toxins and gases, | 0:22:04 | 0:22:07 | |
and that really dreadful smell | 0:22:07 | 0:22:10 | |
is warning you that that's really off. You wouldn't eat this | 0:22:10 | 0:22:13 | |
in a million years, would you? | 0:22:13 | 0:22:16 | |
-If it was the last thing on earth. -If it was the last thing on earth... -GIGGLING | 0:22:16 | 0:22:21 | |
There is an overpowering stench inside the giant Rot Box, too, | 0:22:24 | 0:22:29 | |
as the bacteria breaks down the food | 0:22:29 | 0:22:32 | |
which has now been decaying for two days. | 0:22:32 | 0:22:34 | |
Let's take a closer look at them under the microscope. | 0:22:34 | 0:22:39 | |
This bacterium, Pseudomonas, magnified 7,000 times, | 0:22:39 | 0:22:43 | |
is the most common type of food-rotting bacteria. | 0:22:43 | 0:22:48 | |
There are as many as a trillion individual bacterial cells | 0:22:48 | 0:22:53 | |
in this sample alone. | 0:22:53 | 0:22:56 | |
We can't see bacteria without a microscope, | 0:22:56 | 0:22:59 | |
but they're absolutely everywhere. | 0:22:59 | 0:23:02 | |
They're the most common agent of decay on the planet. | 0:23:02 | 0:23:06 | |
They're the first to attack dead animals | 0:23:06 | 0:23:09 | |
because they're already living on them. | 0:23:09 | 0:23:12 | |
All creatures carry bacteria. | 0:23:12 | 0:23:15 | |
These bacteria were on our chicken when it was alive, | 0:23:15 | 0:23:20 | |
and now that it's dead, | 0:23:20 | 0:23:22 | |
they've quickly begun to decompose its flesh. | 0:23:22 | 0:23:25 | |
-Who can tell me something about bacteria? -They're small. -Very small. | 0:23:33 | 0:23:39 | |
-You need a microscope to see them. -You do need a microscope. | 0:23:39 | 0:23:43 | |
In fact, here is a teaspoonful of soil. | 0:23:43 | 0:23:46 | |
How many bacteria do you think are in that teaspoonful of soil? | 0:23:46 | 0:23:49 | |
-Over a million? -There are 40 million bacteria in that amount of soil. | 0:23:49 | 0:23:54 | |
It's hard to see them, but it's easier to see what they do, | 0:23:54 | 0:23:57 | |
and on here, I've got a film of a chicken that we put in the Rot Box. | 0:23:57 | 0:24:02 | |
Now, look at this. Watch this. | 0:24:02 | 0:24:07 | |
-THEY ALL GASP -What's going on there? | 0:24:07 | 0:24:10 | |
-It's blowing up. -Like a balloon. | 0:24:10 | 0:24:12 | |
It's blowing up like a balloon. | 0:24:12 | 0:24:14 | |
That was a fresh chicken, a completely fresh chicken, | 0:24:14 | 0:24:17 | |
but any piece of fresh meat has bacteria on it, | 0:24:17 | 0:24:21 | |
and because we just left that in the open, the bacteria grew and grew. | 0:24:21 | 0:24:26 | |
Some of these bacteria are really quite hazardous, | 0:24:26 | 0:24:29 | |
so if you ate uncooked meat, you'd be quite ill. | 0:24:29 | 0:24:32 | |
So, with all these bacteria around, how can you make food safe? | 0:24:32 | 0:24:36 | |
-You can refrigerate it. -Yeah. | 0:24:36 | 0:24:38 | |
-You could cook it and then put it back in the fridge. -Absolutely. | 0:24:38 | 0:24:42 | |
-What do organisms need to grow? -Water! -Water, yeah. OK. | 0:24:42 | 0:24:47 | |
So you could dry it, you could freeze it, | 0:24:47 | 0:24:51 | |
you could heat it up, if it's cooked. | 0:24:51 | 0:24:54 | |
-Would cooking a chicken make it safe for ever? -ALL: No. -No, it wouldn't. | 0:24:54 | 0:24:59 | |
-Because it would eventually rot, as well. -Yeah. | 0:24:59 | 0:25:03 | |
So it's all about slowing down the bacterial growth, isn't it? | 0:25:03 | 0:25:08 | |
In the Rot Box, we had the ideal environment for growing bacteria. | 0:25:08 | 0:25:12 | |
It was hot, it was humid, and there was air, | 0:25:12 | 0:25:15 | |
so bearing that in mind, I want to set you a challenge. | 0:25:15 | 0:25:18 | |
I'm going to divide you into two teams | 0:25:18 | 0:25:21 | |
and you're going to a supermarket to find different foods | 0:25:21 | 0:25:25 | |
that have been preserved in different ways. OK? | 0:25:25 | 0:25:27 | |
-Are you up for that? -ALL: Yes! | 0:25:27 | 0:25:30 | |
What's in that? That's good. | 0:25:42 | 0:25:44 | |
CHILDREN CHATTER | 0:25:44 | 0:25:46 | |
-So what shall we get? -We need something sealed, tinned, boxed... | 0:25:46 | 0:25:52 | |
-I think it looks good. -Yeah. | 0:25:52 | 0:25:54 | |
Frozen - ah, here we are! | 0:25:59 | 0:26:02 | |
Oh, cans! Yeah. | 0:26:02 | 0:26:04 | |
On the hunt for baked beans. | 0:26:04 | 0:26:06 | |
There we are. Right. | 0:26:06 | 0:26:08 | |
Done! | 0:26:08 | 0:26:10 | |
Let's start with the girls' team. What have you got? | 0:26:11 | 0:26:14 | |
-Vacuum-packed coffee. -And that's preserved because...? -No air. | 0:26:14 | 0:26:20 | |
There's no air, so that'll slow the bacteria down. | 0:26:20 | 0:26:22 | |
-What else have you got? -Dried mango. | 0:26:22 | 0:26:26 | |
There's no water in it so, again, | 0:26:26 | 0:26:28 | |
that'll stop the bacteria growing. Anything else? | 0:26:28 | 0:26:31 | |
-Gammon. There's no air and it was cold. It was in the fridge. -OK. | 0:26:31 | 0:26:38 | |
It probably has preservatives in it, as well. | 0:26:38 | 0:26:41 | |
They add preservatives to make food last longer. | 0:26:41 | 0:26:44 | |
Good work, girls. Let's see what the boys have got. | 0:26:44 | 0:26:47 | |
-We've for croutons, which we bought because they were dry. -Absolutely. | 0:26:47 | 0:26:52 | |
Dry as a bone in there. OK. What next? | 0:26:52 | 0:26:55 | |
Olives, cos they're in water, | 0:26:55 | 0:26:58 | |
and when they're in water, we thought the bacteria would slow down | 0:26:58 | 0:27:03 | |
because we've never seen rotten olives before. | 0:27:03 | 0:27:07 | |
Water's not going to be good because that'll encourage bacterial growth. | 0:27:07 | 0:27:11 | |
It's actually olive oil in here, and it's been vacuum-packed as well, | 0:27:11 | 0:27:16 | |
so if you keep that shut, it should stay fresh - or not rot - | 0:27:16 | 0:27:21 | |
for quite a long time. | 0:27:21 | 0:27:22 | |
We got baked beans, because they're tinned | 0:27:22 | 0:27:26 | |
and it would be harder for the bacteria to go in | 0:27:26 | 0:27:31 | |
because it's tinned. | 0:27:31 | 0:27:34 | |
So, unless you open that can, | 0:27:34 | 0:27:37 | |
it'll probably stay fresh for a very long time. | 0:27:37 | 0:27:39 | |
I am amazed that nobody picked frozen food, | 0:27:39 | 0:27:44 | |
one of the commonest ways of preserving food. | 0:27:44 | 0:27:47 | |
It's so cold no bacteria will grow in there. Or, if they do, | 0:27:47 | 0:27:51 | |
it'll be very, very slow indeed. | 0:27:51 | 0:27:54 | |
All these are brilliant techniques at slowing down | 0:27:54 | 0:27:57 | |
the growth of bacteria - you exclude water, you keep it cold | 0:27:57 | 0:28:01 | |
or you exclude air - so well done, everybody. | 0:28:01 | 0:28:04 | |
We can often tell when food isn't good to eat by looking at it | 0:28:08 | 0:28:13 | |
or smelling it. | 0:28:13 | 0:28:15 | |
It's easy to see mould at work. | 0:28:15 | 0:28:17 | |
We can't see bacteria, | 0:28:17 | 0:28:19 | |
because they're tiny organisms that can only be seen using a microscope. | 0:28:19 | 0:28:24 | |
But we can see the effects of what we do, | 0:28:24 | 0:28:28 | |
and we can smell the gases they produce when they're attacking food. | 0:28:28 | 0:28:32 | |
This should warn us not to eat it. | 0:28:32 | 0:28:34 | |
Bacteria are everywhere, and are already on foods like meat and fish | 0:28:34 | 0:28:38 | |
when you buy them. | 0:28:38 | 0:28:40 | |
They are the most common agents of decay on the planet. | 0:28:40 | 0:28:44 | |
Inside this large glass box, | 0:28:51 | 0:28:54 | |
something extraordinary is happening. | 0:28:54 | 0:28:58 | |
Food is being left to rot for eight weeks | 0:28:58 | 0:29:01 | |
in our own unique laboratory. | 0:29:01 | 0:29:04 | |
This is an investigation into nature's biggest | 0:29:07 | 0:29:11 | |
and best recycler - decay. | 0:29:11 | 0:29:15 | |
And it's being done on a scale that has never been tried before. | 0:29:15 | 0:29:20 | |
I'm Dr George McGavin. | 0:29:20 | 0:29:22 | |
I'm a biologist with a particular passion for insects. | 0:29:22 | 0:29:26 | |
The Rot Box detectives - Iona, Rosie, | 0:29:26 | 0:29:30 | |
Ruaridh, Mram and Jamie - | 0:29:30 | 0:29:33 | |
are going to help me investigate | 0:29:33 | 0:29:36 | |
the amazing world of rot and decay. | 0:29:36 | 0:29:40 | |
'We'll see flies...' | 0:29:44 | 0:29:46 | |
Oh. Oh-hoo! | 0:29:46 | 0:29:47 | |
Look at this. | 0:29:47 | 0:29:49 | |
'..mould...' | 0:29:49 | 0:29:51 | |
Ah! That's incredible. | 0:29:51 | 0:29:53 | |
'..and bacteria.' | 0:29:53 | 0:29:55 | |
The bacteria have been hard at work. | 0:29:57 | 0:29:59 | |
At Rot Box detective HQ, we're discovering more about bacteria. | 0:30:02 | 0:30:08 | |
Now, who can tell me something about bacteria? | 0:30:08 | 0:30:11 | |
-There's some good bacteria and some bad bacteria. -True. | 0:30:11 | 0:30:15 | |
-They're absolutely everywhere. -That is completely correct. | 0:30:15 | 0:30:19 | |
I went out to the garden earlier and I collected some rainwater. | 0:30:19 | 0:30:22 | |
There are one million bacteria just in that little spoonful there. | 0:30:22 | 0:30:28 | |
-One million! -Wow. -In there. | 0:30:28 | 0:30:32 | |
Now, the one thing about bacteria, of course, is, as you said, | 0:30:32 | 0:30:35 | |
there's good and bad ones. | 0:30:35 | 0:30:38 | |
What would happen if a bad bacterium had got inside you? | 0:30:38 | 0:30:41 | |
-You'd get a tummy bug. -Absolutely. | 0:30:41 | 0:30:45 | |
How do you think the bacteria get inside you? | 0:30:45 | 0:30:48 | |
If you eat something but before you ate it, you didn't wash your hands. | 0:30:48 | 0:30:53 | |
Absolutely right. That is the commonest route to get internal infections, | 0:30:53 | 0:30:58 | |
internal bacteria. | 0:30:58 | 0:30:59 | |
Now, I've got a very smart trick that will show us | 0:30:59 | 0:31:03 | |
how easy it is to transfer bacteria from person to person to person. | 0:31:03 | 0:31:08 | |
OK? | 0:31:08 | 0:31:09 | |
Now, we can't see bacteria on our skin without very special equipment, | 0:31:11 | 0:31:15 | |
but I can show you how they spread around. | 0:31:15 | 0:31:18 | |
'I'm going to show the team how easy it is to spread bacteria | 0:31:18 | 0:31:23 | |
'by using this special cream that glows under ultraviolet light.' | 0:31:23 | 0:31:28 | |
You can't see it there, yeah? OK? | 0:31:28 | 0:31:32 | |
-But if I now put this under my hands, you can see... -ALL: Ohhh! | 0:31:32 | 0:31:36 | |
..it's everywhere, OK? | 0:31:37 | 0:31:41 | |
Now, hold your hands up, Iona. Clean? In the ultraviolet. Other side. | 0:31:41 | 0:31:44 | |
Completely clean. | 0:31:44 | 0:31:46 | |
Now, if I shake your hand... | 0:31:46 | 0:31:48 | |
Hello, nice to see you! And now you put your hand under the there. | 0:31:48 | 0:31:52 | |
ALL LAUGH | 0:31:52 | 0:31:53 | |
Whoa! Now, if you shake hands with Ruaridh... | 0:31:53 | 0:31:56 | |
Hello! Shake hands. And underneath there - let's see. | 0:31:59 | 0:32:02 | |
Ew! Yes, it's spread, from me to you to you, right? | 0:32:02 | 0:32:09 | |
Very, very easy. | 0:32:09 | 0:32:12 | |
Now, imagine this was bacteria. OK? | 0:32:12 | 0:32:15 | |
I'm going to squidge it in your hands, OK, and rub that all in. | 0:32:15 | 0:32:20 | |
'Some bacteria can cause disease and make us feel unwell. | 0:32:20 | 0:32:24 | |
'You might know them as germs. | 0:32:24 | 0:32:26 | |
'They can get onto my hands when we sneeze or cough into them, or when we use the toilet. | 0:32:26 | 0:32:30 | |
'That's why it's important to wash your hands properly. | 0:32:30 | 0:32:34 | |
'I'm testing how well Jamie and Rosie wash their hands.' | 0:32:34 | 0:32:37 | |
Now, let's just check under the ultraviolet light, | 0:32:37 | 0:32:41 | |
see how glowing your hands are. | 0:32:41 | 0:32:43 | |
Ooh, yes! | 0:32:43 | 0:32:45 | |
Come on, Jamie. Squidge round. Oh, yes! Oh, yeah. | 0:32:45 | 0:32:50 | |
Go wash your hands. | 0:32:50 | 0:32:52 | |
Let's see how well they do. | 0:32:52 | 0:32:55 | |
-Ah-ha! Right, are your hands washed? -Yes. -Let me inspect them. | 0:32:57 | 0:33:01 | |
Do the old test. | 0:33:01 | 0:33:02 | |
Oh, yes, now if I was a parent, I'd say, "That's very good. | 0:33:02 | 0:33:06 | |
"Very good. Very clean." But is it? | 0:33:06 | 0:33:08 | |
Rosie, stick your hands under the ultraviolet. | 0:33:08 | 0:33:11 | |
-Oh-hoo-hoo! Eugh! -ALL: Eugh! | 0:33:11 | 0:33:13 | |
Not so good. | 0:33:13 | 0:33:14 | |
It's all on your fingernail. It's all over your thumb. | 0:33:14 | 0:33:18 | |
Oh, yes, not so clean, but not bad. OK? | 0:33:18 | 0:33:21 | |
Jamie, stick your hand in there, son. | 0:33:21 | 0:33:23 | |
Let's see what we've got on yours. | 0:33:23 | 0:33:25 | |
ALL: Eugh! | 0:33:25 | 0:33:28 | |
Oh, yeah. I think Rosie won that one. Yeah, definitely, yeah. | 0:33:28 | 0:33:33 | |
It's on all your fingernails, | 0:33:33 | 0:33:35 | |
over the front and back of your hand, in the creases of your thumbs and fingers. | 0:33:35 | 0:33:39 | |
Not good enough. | 0:33:39 | 0:33:41 | |
So you see how you think you've washed your hands carefully enough, | 0:33:41 | 0:33:46 | |
but actually to wash your hands really carefully and properly to remove bacteria | 0:33:46 | 0:33:50 | |
it's quite hard. | 0:33:50 | 0:33:51 | |
The correct way to wash your hands, of course, using soap and hot water | 0:33:51 | 0:33:56 | |
is to put the soap there, rub, rub, rub, right? | 0:33:56 | 0:33:59 | |
Both sides and then interlock your fingers like this | 0:33:59 | 0:34:02 | |
and then do the backs of your fingers like that, | 0:34:02 | 0:34:06 | |
then you do your thumbs, yes? | 0:34:06 | 0:34:07 | |
And then your thumbs like that, OK? | 0:34:07 | 0:34:10 | |
And then the back of your hands like that. | 0:34:10 | 0:34:13 | |
And then rinse it all off, OK? | 0:34:13 | 0:34:15 | |
So it's actually quite hard work. | 0:34:15 | 0:34:18 | |
Bacteria are the one thing | 0:34:18 | 0:34:21 | |
that we didn't have to put inside the box because they're already there. | 0:34:21 | 0:34:25 | |
They're everywhere - | 0:34:25 | 0:34:27 | |
tiny living things, or micro-organisms, that you can't see without a microscope. | 0:34:27 | 0:34:34 | |
In the Rot Box, we have an incredible microscope | 0:34:34 | 0:34:38 | |
that magnifies the bacteria a breathtaking 7,000 times. | 0:34:38 | 0:34:42 | |
This allows us to have a much more detailed look. | 0:34:42 | 0:34:46 | |
With enough food and water, | 0:34:46 | 0:34:49 | |
the numbers of bacteria can increase alarmingly fast. | 0:34:49 | 0:34:53 | |
They increase by dividing into two every 30 minutes, | 0:34:53 | 0:34:57 | |
so after just 24 hours, | 0:34:57 | 0:35:00 | |
one bacterium becomes just over 281 billion bacteria. | 0:35:00 | 0:35:07 | |
They make up the largest number of living organisms on the planet. | 0:35:07 | 0:35:13 | |
There are trillions and trillions and trillions of micro-organisms around the earth. | 0:35:13 | 0:35:19 | |
But they're not all harmful, some of them help us. | 0:35:19 | 0:35:23 | |
Importantly, bacteria live in our gut, helping us to digest our food. | 0:35:23 | 0:35:29 | |
Now there are bacteria all over us obviously, | 0:35:32 | 0:35:35 | |
but there's also lots of bacteria inside us. | 0:35:35 | 0:35:37 | |
-Where do you think you could find lots of bacteria? -In your stomach. -Yeah, lots of bacteria. | 0:35:37 | 0:35:44 | |
-Up your nose. -Yes, lots of bacteria there. | 0:35:44 | 0:35:46 | |
-In your ears. -In your ears. Yes. Anywhere else? | 0:35:46 | 0:35:50 | |
-In your mouth. -Particularly in your mouth, | 0:35:50 | 0:35:52 | |
so lots of bacteria in there, some are good, some are bad. | 0:35:52 | 0:35:56 | |
What I want to show you is how important it is to brush your teeth. | 0:35:56 | 0:36:01 | |
I'm sending Iona and Mram off to brush their teeth so I can demonstrate | 0:36:01 | 0:36:05 | |
how important it is to do it properly. | 0:36:05 | 0:36:09 | |
-Have you brushed them properly? -Yes. -Yes. | 0:36:12 | 0:36:14 | |
Well, I've got here little special tablets called disclosing tablets | 0:36:14 | 0:36:18 | |
and you can have one each, right? | 0:36:18 | 0:36:21 | |
It will show if you've really brushed your teeth properly, | 0:36:21 | 0:36:26 | |
so what I want you do to is... | 0:36:26 | 0:36:28 | |
in your mouth, roll it around your tongue | 0:36:28 | 0:36:30 | |
and get all the liquid over your teeth and gums, | 0:36:30 | 0:36:33 | |
do not swallow it, | 0:36:33 | 0:36:34 | |
and then, once you've done that, go to the kitchen | 0:36:34 | 0:36:36 | |
and spit it out and rinse your mouth out with fresh water | 0:36:36 | 0:36:40 | |
and then come back. | 0:36:40 | 0:36:41 | |
CHILDREN GIGGLE | 0:36:42 | 0:36:43 | |
Now what this does is, | 0:36:45 | 0:36:46 | |
the red dye sticks to the plaque. | 0:36:46 | 0:36:49 | |
'Plaque is a sticky film containing bacteria | 0:36:49 | 0:36:52 | |
'that can build up on your teeth. | 0:36:52 | 0:36:54 | |
'The bacteria love to feed on sugar and when they feed, | 0:36:54 | 0:36:57 | |
'they make acid which can rot your teeth.' | 0:36:57 | 0:37:00 | |
It's very important to brush all that plaque off, | 0:37:00 | 0:37:03 | |
that plaque bacteria off, | 0:37:03 | 0:37:05 | |
and the red tablets show where the plaque is. | 0:37:05 | 0:37:08 | |
Now you've brushed your teeth properly. Let's just see. | 0:37:08 | 0:37:12 | |
You've got a little bit of plaque just on the bottom of that one. | 0:37:12 | 0:37:16 | |
Yes, that's not too bad at all. | 0:37:17 | 0:37:21 | |
Let me see. | 0:37:21 | 0:37:22 | |
Open up. | 0:37:23 | 0:37:25 | |
Now there's some plaque on the edge of that tooth there, | 0:37:25 | 0:37:28 | |
some plaque along the edge of that side. | 0:37:28 | 0:37:30 | |
Now the ones who haven't brushed their teeth, right? Oh! | 0:37:32 | 0:37:35 | |
Oh-h! | 0:37:35 | 0:37:37 | |
Let's see yours. | 0:37:37 | 0:37:39 | |
Go, "Nnnnyah!" | 0:37:39 | 0:37:40 | |
Yeah. Ruaridh, open up. Oh! | 0:37:42 | 0:37:47 | |
I think you just had it on your tongue. | 0:37:47 | 0:37:49 | |
You didn't roll it around your teeth. | 0:37:49 | 0:37:51 | |
OK, that's quite clear to me that the two who've brushed their teeth | 0:37:51 | 0:37:57 | |
have done quite a good job and you've removed most of the plaque. | 0:37:57 | 0:38:01 | |
I'm impressed with you two. | 0:38:01 | 0:38:03 | |
Bacteria are micro-organisms, tiny single-celled creatures | 0:38:08 | 0:38:12 | |
that can't be seen without a microscope. | 0:38:12 | 0:38:15 | |
They're absolutely everywhere | 0:38:17 | 0:38:19 | |
and can multiply in numbers incredibly quickly. | 0:38:19 | 0:38:22 | |
As a result, there are trillions and trillions and trillions of them on earth. | 0:38:22 | 0:38:28 | |
Not all bacteria are harmful, some can be helpful too. | 0:38:28 | 0:38:33 | |
They're very easily spread, | 0:38:33 | 0:38:35 | |
so it's important to wash hands and brush teeth thoroughly. | 0:38:35 | 0:38:38 | |
This will help to stop the spread of harmful bacteria | 0:38:38 | 0:38:42 | |
or germs. | 0:38:42 | 0:38:44 | |
Inside this large glass box, | 0:38:55 | 0:38:58 | |
something extraordinary is happening. | 0:38:58 | 0:39:01 | |
Food is being left to rot for eight weeks in our own unique laboratory. | 0:39:01 | 0:39:08 | |
This is an investigation | 0:39:11 | 0:39:12 | |
into nature's biggest and best recycler - decay. | 0:39:12 | 0:39:18 | |
And it's being done on a scale that has never been tried before. | 0:39:18 | 0:39:23 | |
I'm Dr George McGavin. | 0:39:23 | 0:39:26 | |
I'm a biologist with a particular passion for insects. | 0:39:26 | 0:39:30 | |
The Rot Box detectives, Iona, Rosie, | 0:39:30 | 0:39:34 | |
Ruaridh, Mram and Jamie | 0:39:34 | 0:39:38 | |
are going to help me investigate the amazing world of rot and decay. | 0:39:38 | 0:39:43 | |
'There's mould...' | 0:39:47 | 0:39:49 | |
The mould has just covered that entire box. | 0:39:49 | 0:39:53 | |
'..bacteria...' | 0:39:53 | 0:39:54 | |
-Where you can see those glowing bits... -Yeah. | 0:39:54 | 0:39:57 | |
..that's bacteria. | 0:39:57 | 0:39:59 | |
'..and flies.' | 0:39:59 | 0:40:00 | |
It's pretty unpleasant, I've got to say. | 0:40:01 | 0:40:03 | |
'It has taken eight months to build this giant Rot Box | 0:40:07 | 0:40:10 | |
'and now conditions are perfect inside. | 0:40:10 | 0:40:14 | |
'It's warm, there's water, air and plenty of food - | 0:40:15 | 0:40:18 | |
'all the things decay loves to feast and grow on. | 0:40:18 | 0:40:24 | |
'In the real world, female flies find the stench of rot irresistible | 0:40:24 | 0:40:28 | |
'and will be attracted to it instantly, | 0:40:28 | 0:40:31 | |
'as they find it the ideal place to lay their eggs, | 0:40:31 | 0:40:35 | |
'but because our Rot Box is sealed, no smell is escaping, | 0:40:35 | 0:40:39 | |
'so we need to put the flies into the box.' | 0:40:39 | 0:40:42 | |
And there they go. | 0:40:42 | 0:40:44 | |
Well, that's it. We're up and running | 0:40:44 | 0:40:46 | |
and it's time to leave all this to the agents of decay. | 0:40:46 | 0:40:50 | |
Back at Rot Box Detective HQ, | 0:40:55 | 0:40:57 | |
we wanted to investigate flies in more detail. | 0:40:57 | 0:41:01 | |
An adult fly can live up to five days, | 0:41:01 | 0:41:04 | |
but in such a short life, this tiny creature is incredibly busy. | 0:41:04 | 0:41:09 | |
This is a fly actually laying an egg. Now look at that. | 0:41:09 | 0:41:13 | |
See? The female's got this long bit at the back of the abdomen | 0:41:13 | 0:41:16 | |
through which the eggs pass, | 0:41:16 | 0:41:17 | |
so she's actually laying eggs there on some meat. | 0:41:17 | 0:41:21 | |
ALL: Wow! | 0:41:21 | 0:41:23 | |
-Oh, that's a fly! -Oh, right! | 0:41:23 | 0:41:27 | |
Now if we go to the maggot, | 0:41:27 | 0:41:29 | |
when those eggs hatch and the little fly larvae, | 0:41:29 | 0:41:32 | |
which are called maggots, hatch out, | 0:41:32 | 0:41:34 | |
they've got little sharp hooks at the head end | 0:41:34 | 0:41:36 | |
with which they tear the meat. Look at that. | 0:41:36 | 0:41:39 | |
-Look. See? -That's horrible. | 0:41:39 | 0:41:41 | |
And they just rip through the meat. | 0:41:41 | 0:41:44 | |
Now the great thing about fly maggots is that they can breathe through special holes | 0:41:44 | 0:41:48 | |
at their rear end called spiracles, | 0:41:48 | 0:41:51 | |
so we breathe through our mouths, fly larvae haven't got that - | 0:41:51 | 0:41:54 | |
they breathe through a system of tubes, | 0:41:54 | 0:41:57 | |
so it can feed and breathe at the same time. | 0:41:57 | 0:41:59 | |
And the last film is a fly after it's fully-grown, | 0:41:59 | 0:42:03 | |
after the maggot's eaten all it can eat, | 0:42:03 | 0:42:05 | |
it then becomes a pupae and it stays in there | 0:42:05 | 0:42:09 | |
and it emerges as an adult fly and here is a film. | 0:42:09 | 0:42:12 | |
Look at this. Wow! here is a fly actually emerging, | 0:42:12 | 0:42:16 | |
and after it's pushed itself out, it dries one wing, | 0:42:16 | 0:42:19 | |
and then it dries the other wing | 0:42:19 | 0:42:22 | |
and then it flies off. | 0:42:22 | 0:42:23 | |
Cool! | 0:42:23 | 0:42:25 | |
Oh, look, now it's flying. | 0:42:25 | 0:42:27 | |
Fantastic. | 0:42:27 | 0:42:29 | |
There you go. | 0:42:29 | 0:42:30 | |
We're making flytraps | 0:42:34 | 0:42:36 | |
to see how many flies will smell our rotting fish, | 0:42:36 | 0:42:38 | |
so that we can have a closer look at them in action. | 0:42:38 | 0:42:42 | |
That's the trap made. What we have to do now to attract the flies is to put in the bait. | 0:42:51 | 0:42:57 | |
Now, do you want a head or a tail? | 0:42:57 | 0:42:59 | |
-A head. -Head. All right. Hold that. | 0:42:59 | 0:43:01 | |
We should have one head left. Oh, there it is. | 0:43:01 | 0:43:05 | |
-ALL: Eugh! -Eugh! | 0:43:05 | 0:43:06 | |
Lovely fishy bait. Smelly, smelly. And then you put that in. | 0:43:06 | 0:43:09 | |
Stick it in there. So there we are. | 0:43:09 | 0:43:12 | |
Now, how do you think the trap works? | 0:43:12 | 0:43:16 | |
The fly goes in that hole and then it gets stuck and then it can't fly out. | 0:43:16 | 0:43:20 | |
-Yeah, it's like a creel or a lobster pot. -Can't it go out there? | 0:43:20 | 0:43:25 | |
Some flies could fly out again, but flies are not terribly bright, | 0:43:25 | 0:43:29 | |
and after they're in there, they tend to fly up, | 0:43:29 | 0:43:32 | |
so they don't find the hole very easily, | 0:43:32 | 0:43:36 | |
so although some of them will escape, not many of them escape. | 0:43:36 | 0:43:39 | |
And there is your completed flytrap. | 0:43:39 | 0:43:42 | |
-Awesome. -Now where would be the best place to hang them up? | 0:43:42 | 0:43:46 | |
A bright place, somewhere really warm, so it attracts more flies | 0:43:46 | 0:43:50 | |
-and the fish gets more rotten. -Absolutely. | 0:43:50 | 0:43:53 | |
I'll bet you anything, within 30 seconds, there'll be flies in there. | 0:43:53 | 0:43:57 | |
Oh, look, there's a fly in it already. | 0:43:57 | 0:43:59 | |
Oh, see how efficient it is. | 0:43:59 | 0:44:01 | |
Right, let's go. | 0:44:01 | 0:44:04 | |
Now why do you think the adult flies are attracted to the dead fish? | 0:44:07 | 0:44:11 | |
Because they want to leave an egg there? | 0:44:11 | 0:44:16 | |
Absolutely. That's where they lay their eggs. | 0:44:16 | 0:44:18 | |
Now adult flies don't live very long - | 0:44:18 | 0:44:20 | |
they only live about five or six days, | 0:44:20 | 0:44:23 | |
so when they're adult, | 0:44:23 | 0:44:24 | |
the only job they have is to mate and to lay their eggs. | 0:44:24 | 0:44:27 | |
I'm going to hang my trap up on this bolt over here, | 0:44:27 | 0:44:31 | |
-and then we'll hang yours up on those trees, OK? -Mm-hm. | 0:44:31 | 0:44:34 | |
'A few hours later, | 0:44:45 | 0:44:47 | |
'and we're back at the traps to see if they're a success.' | 0:44:47 | 0:44:50 | |
Right, let's see who's caught the most flies. | 0:44:50 | 0:44:53 | |
-Whose trap is this one? -Me and Rosie. | 0:44:53 | 0:44:55 | |
Right, well, you've got four flies on the inside, | 0:44:55 | 0:44:59 | |
quite a few on the outside and you've got lots of eggs on the head, | 0:44:59 | 0:45:03 | |
so that's really good. | 0:45:03 | 0:45:04 | |
Look, we nearly got one! | 0:45:04 | 0:45:06 | |
Let me see. Oh, you have got small ones on the outside. | 0:45:06 | 0:45:09 | |
You've got one fly at the back there | 0:45:09 | 0:45:12 | |
and no eggs. | 0:45:12 | 0:45:14 | |
Mmm? | 0:45:14 | 0:45:16 | |
And now, my trap... | 0:45:17 | 0:45:19 | |
..ooh, look at that. | 0:45:20 | 0:45:22 | |
-ALL: Oh-h! -There's at least one, two, three, four, five, six, seven flies in there - | 0:45:22 | 0:45:26 | |
three species and lots of eggs. Look at that. | 0:45:26 | 0:45:29 | |
You can see all the eggs over the mouth | 0:45:29 | 0:45:32 | |
and in the mouth and on the head end, see? It could all change, | 0:45:32 | 0:45:36 | |
-because there might be more flies in your traps tomorrow. -Yeah. | 0:45:36 | 0:45:39 | |
After five weeks, the Rot Box has begun to look like a giant flytrap. | 0:45:43 | 0:45:49 | |
There are now up to 10,000 flies trapped inside. | 0:45:49 | 0:45:52 | |
Outside in the real world, these flies would have escaped | 0:45:55 | 0:45:59 | |
out of a open window, but because the box is sealed, | 0:45:59 | 0:46:02 | |
they've got nowhere to go and food is running out fast. | 0:46:02 | 0:46:07 | |
I'm worried this huge number of flies will upset the balance of life in the box, | 0:46:08 | 0:46:13 | |
so I've decided to go in and take control. | 0:46:13 | 0:46:17 | |
Well, there are just now simply too many flies in here. | 0:46:23 | 0:46:27 | |
It's becoming quite unpleasant, | 0:46:27 | 0:46:29 | |
and it's causing a problem, | 0:46:29 | 0:46:30 | |
because of the flyspeck, that's their excrement, | 0:46:30 | 0:46:33 | |
which they leave on the surfaces inside the glass everywhere, | 0:46:33 | 0:46:36 | |
so it's time I tried to reduce them a little bit... | 0:46:36 | 0:46:40 | |
..manually. | 0:46:41 | 0:46:43 | |
The trouble is, they're flying quite low | 0:46:43 | 0:46:47 | |
and they're sitting on surfaces - it's actually very hard to get them. | 0:46:47 | 0:46:51 | |
It's no wonder flies are so hard to capture. | 0:46:57 | 0:46:59 | |
Their compound eyes give them all-round vision, | 0:46:59 | 0:47:02 | |
so they can respond to movement in a fraction of a second. | 0:47:02 | 0:47:07 | |
I'm never going to win this fly hunt. | 0:47:09 | 0:47:11 | |
'The team and I are taking the fly hunt outside.' | 0:47:16 | 0:47:19 | |
Right, well, we've been quite lucky with the rain. | 0:47:19 | 0:47:22 | |
Yep. | 0:47:22 | 0:47:23 | |
Oh, look at this. Look what I've found. | 0:47:24 | 0:47:27 | |
Look. | 0:47:27 | 0:47:28 | |
-Oh, wow! -Look at that. -Aw-w! | 0:47:30 | 0:47:34 | |
Who knows what that is? | 0:47:34 | 0:47:36 | |
-A pheasant. -Yeah, it's a female pheasant | 0:47:36 | 0:47:38 | |
and I think it's probably been hit by a car, actually. | 0:47:38 | 0:47:40 | |
In the real world, everything dies at some point, | 0:47:40 | 0:47:44 | |
and when they do, bacteria start to act on them, breaking it down. | 0:47:44 | 0:47:49 | |
They produce smells, bad odours which attract organisms, | 0:47:49 | 0:47:52 | |
and if you remember back to your flytraps, | 0:47:52 | 0:47:55 | |
the flies were attracted to the decaying fish pretty quickly, | 0:47:55 | 0:47:58 | |
and the same thing will happen here. | 0:47:58 | 0:48:00 | |
Now what would happen if we didn't have flies laying their eggs in it, | 0:48:00 | 0:48:04 | |
and maggots eating it and other animals taking it away? | 0:48:04 | 0:48:07 | |
-What would happen? -There'd be, like, loads of dead animals everywhere | 0:48:07 | 0:48:10 | |
-and it would smell. -Exactly. | 0:48:10 | 0:48:12 | |
Flies and other things that recycle dead animals | 0:48:12 | 0:48:16 | |
really perform a fantastic job for us. | 0:48:16 | 0:48:19 | |
Flies, particularly, are one of the most important recycling animals. | 0:48:19 | 0:48:23 | |
Right, let's go. | 0:48:23 | 0:48:24 | |
Back at the Rot Box, the cycle of life continues. | 0:48:32 | 0:48:35 | |
Female flies are attracted to the rotting food, | 0:48:36 | 0:48:39 | |
laying up to 300 eggs at a time. | 0:48:39 | 0:48:42 | |
The eggs hatch into larvae called maggots. | 0:48:43 | 0:48:46 | |
Maggots are amazing feeders. They use sharp hooks to eat | 0:48:46 | 0:48:50 | |
and breathe through air holes called spiracles in their rear end. | 0:48:50 | 0:48:55 | |
The maggots then become pupae | 0:48:55 | 0:48:57 | |
from which young flies emerge and the whole cycle will begin again. | 0:48:57 | 0:49:02 | |
So even though flies spread bacteria and mould | 0:49:02 | 0:49:05 | |
by landing on fresh food, | 0:49:05 | 0:49:06 | |
they have a very important job as recyclers. | 0:49:06 | 0:49:10 | |
Inside this large glass box | 0:49:17 | 0:49:20 | |
something extraordinary is happening. | 0:49:20 | 0:49:23 | |
Food is being left to rot for eight weeks in our own unique laboratory. | 0:49:23 | 0:49:30 | |
This is an investigation into nature's biggest and best recycler... | 0:49:33 | 0:49:38 | |
..decay, | 0:49:39 | 0:49:40 | |
and it's being done on a scale | 0:49:40 | 0:49:42 | |
that has never been tried before. | 0:49:42 | 0:49:47 | |
I'm Dr George McGavin. | 0:49:47 | 0:49:48 | |
I'm a biologist with a particular passion for insects. | 0:49:48 | 0:49:52 | |
The Rot Box detectives, Iona, Rosie, | 0:49:52 | 0:49:56 | |
Ruaridh, Mram and Jamie | 0:49:56 | 0:50:00 | |
are going to help me investigate the amazing world of rot and decay. | 0:50:00 | 0:50:06 | |
'There's mound...' | 0:50:08 | 0:50:10 | |
The melon's just incredible. It's really been hammered. Look at that. | 0:50:10 | 0:50:14 | |
'..flies...' | 0:50:14 | 0:50:15 | |
The number of flies has absolutely skyrocketed. | 0:50:15 | 0:50:19 | |
'..and bacteria.' | 0:50:19 | 0:50:20 | |
As well as food, there's a compost heap in the Rot Box, | 0:50:28 | 0:50:31 | |
which includes vegetable waste and leaves. | 0:50:31 | 0:50:34 | |
This is a great place to see decomposition in action. | 0:50:36 | 0:50:41 | |
We've been adding green material to the top, | 0:50:41 | 0:50:44 | |
but if we clear the top layers down, what's been happening in here | 0:50:44 | 0:50:47 | |
is lots and lots of woodlice, worms beetles have been working away | 0:50:47 | 0:50:52 | |
at the green material, breaking it down, | 0:50:52 | 0:50:55 | |
decomposing it into smaller material, | 0:50:55 | 0:50:57 | |
smaller particles, | 0:50:57 | 0:50:59 | |
and that is then available for use | 0:50:59 | 0:51:01 | |
by the billions of bacteria and fungi which are also in here. | 0:51:01 | 0:51:05 | |
We'll be back to have a much more detailed look at these later on. | 0:51:05 | 0:51:10 | |
Back at Rot Box Detective HQ, | 0:51:15 | 0:51:17 | |
we are collecting leaves for our compost bin. | 0:51:17 | 0:51:20 | |
It's the best place to see natural recycling at work. | 0:51:20 | 0:51:25 | |
Right, let's come over to the compost bin. | 0:51:29 | 0:51:34 | |
Let me take that. | 0:51:34 | 0:51:35 | |
-Now do any of you do recycling? -Yeah, I do. | 0:51:35 | 0:51:40 | |
Glass, paper and cardboard. | 0:51:40 | 0:51:42 | |
-OK. -We recycle the garbage in our garden. -Right. | 0:51:42 | 0:51:45 | |
-Oh, you do? So you've got a brown bin, have you? -Yeah. | 0:51:45 | 0:51:50 | |
I've got a brown bin so I put, like, hedge cuttings and grass cuttings in it. | 0:51:50 | 0:51:55 | |
-So all the waste from the garden ends up in here? -Yeah. -Yeah. | 0:51:55 | 0:51:58 | |
That's what we're going to with the leaves we've raked up, | 0:51:58 | 0:52:01 | |
but before we empty it in, put your hand in there, tell me what you feel. | 0:52:01 | 0:52:06 | |
-Leaves. -Nothing. -Oh, it's warm. | 0:52:06 | 0:52:08 | |
It's warm! | 0:52:08 | 0:52:09 | |
-Oh, yeah. -Wow! | 0:52:09 | 0:52:11 | |
Well, that's the bacteria breaking the stuff down. | 0:52:11 | 0:52:14 | |
-Right, empty the leaves in. -Will there be enough room? -Oh, yeah. | 0:52:14 | 0:52:18 | |
-Oh, yeah. -There we are. -Sorry. -Right. | 0:52:18 | 0:52:23 | |
Who knows where this goes? | 0:52:23 | 0:52:24 | |
Once you've filled up your brown bin, where does it go? | 0:52:24 | 0:52:28 | |
-Bin lorry. -Ah, well, I'm going to show you. | 0:52:28 | 0:52:31 | |
The leaves that we collected in the garden, we raked them up into the brown bin. | 0:52:47 | 0:52:52 | |
The brown bin gets picked up by the truck, | 0:52:52 | 0:52:54 | |
and the trucks all come here and there's one arriving now. | 0:52:54 | 0:52:58 | |
They open the back, all the green material gets pushed out, | 0:52:58 | 0:53:01 | |
and then a scoop comes and takes it to a shredder. | 0:53:01 | 0:53:05 | |
That's where the whole process begins. | 0:53:05 | 0:53:07 | |
It falls through these two huge rotating bars. | 0:53:07 | 0:53:12 | |
It grinds it all up | 0:53:12 | 0:53:14 | |
and it spits it out the bottom onto a bed | 0:53:14 | 0:53:16 | |
and then it gets carried out there into a pile | 0:53:16 | 0:53:19 | |
and the reason they do that is to break up | 0:53:19 | 0:53:21 | |
all that material into smaller bits, | 0:53:21 | 0:53:24 | |
so that it has a larger surface area, | 0:53:24 | 0:53:27 | |
so the bacteria can get to work on it. | 0:53:27 | 0:53:28 | |
Right, now, this... is where it all comes. | 0:53:41 | 0:53:44 | |
So, once it's been through the shredder, | 0:53:44 | 0:53:47 | |
it gets piled up in these long rows. | 0:53:47 | 0:53:49 | |
Now, the reason they don't pile it in one great pile | 0:53:49 | 0:53:52 | |
is if they had it in one huge pile, it would go all slimy, | 0:53:52 | 0:53:56 | |
there'd be no oxygen in the middle. | 0:53:56 | 0:53:57 | |
It would go all horrible. | 0:53:57 | 0:53:59 | |
So they have it in these rows so they get lots of air in there | 0:53:59 | 0:54:02 | |
and the air helps the bacteria and the decomposition. | 0:54:02 | 0:54:04 | |
And what happens next is they put this through a screen or a sieve, | 0:54:04 | 0:54:09 | |
it's like a giant sieve, and they take out all the big bits. | 0:54:09 | 0:54:13 | |
So all you're left with is fine compost. | 0:54:13 | 0:54:16 | |
-How hot do you think it is in there? -20 degrees? -No. | 0:54:16 | 0:54:19 | |
-40? -No. Hotter than that. | 0:54:19 | 0:54:22 | |
-50 degrees? -Hotter than that. | 0:54:22 | 0:54:24 | |
-85 degrees. -That's a pretty good estimate. Let's see how hot it is. | 0:54:24 | 0:54:29 | |
'I'm using a thermal probe to measure the heat inside the pile.' | 0:54:29 | 0:54:33 | |
Let's see exactly how hot it is. | 0:54:34 | 0:54:36 | |
47, 49...50... | 0:54:42 | 0:54:45 | |
Going up! | 0:54:46 | 0:54:48 | |
-Will it make 60? -Yes, it will. | 0:54:49 | 0:54:51 | |
-It will, it will! -59.9... | 0:54:51 | 0:54:55 | |
60! | 0:54:55 | 0:54:56 | |
60 and rising. Now, the reason it gets really hot in here | 0:54:56 | 0:54:59 | |
is because there's billions of bacteria in here, | 0:54:59 | 0:55:02 | |
breaking all the material down | 0:55:02 | 0:55:04 | |
and as they break it down, they produce large amounts of heat. | 0:55:04 | 0:55:08 | |
What's the highest? | 0:55:08 | 0:55:09 | |
Some of these piles have even had fires in them | 0:55:09 | 0:55:13 | |
cos it's just so hot. That's the power of bacteria. | 0:55:13 | 0:55:15 | |
Now, once they've taken out all the big bits, | 0:55:19 | 0:55:21 | |
all the big bits of wood and roots and stuff, | 0:55:21 | 0:55:23 | |
the end result of all that recycling | 0:55:23 | 0:55:25 | |
is this beautiful, beautiful compost. | 0:55:25 | 0:55:28 | |
And that goes straight on your garden. | 0:55:28 | 0:55:30 | |
Now, we've speeded it up by having it broken down into smaller bits, | 0:55:30 | 0:55:34 | |
but recycling is happening all the time, all around us. | 0:55:34 | 0:55:38 | |
Back in the giant Rot Box, we can take a much closer look | 0:55:42 | 0:55:45 | |
at how recycling is happening in the compost heap. | 0:55:45 | 0:55:48 | |
As all gardeners know, compost turns dead plants | 0:55:54 | 0:55:57 | |
into a form of nutrient that new plants can use. | 0:55:57 | 0:56:01 | |
On the surface, animals like snails, slugs | 0:56:04 | 0:56:06 | |
and worms begin the process by eating the remains of plants, | 0:56:06 | 0:56:10 | |
helping to break them into smaller pieces. | 0:56:10 | 0:56:13 | |
Other small animals, like these mites, | 0:56:16 | 0:56:18 | |
feed on the waste products these creatures leave behind. | 0:56:18 | 0:56:22 | |
This process continues down through the compost, | 0:56:24 | 0:56:27 | |
with ever-smaller organisms reducing the plant waste | 0:56:27 | 0:56:30 | |
to ever-smaller pieces, until tiny micro-fauna | 0:56:30 | 0:56:35 | |
and bacteria are able to break down the very cells of the plants. | 0:56:35 | 0:56:39 | |
A teaspoon of soil contains four billion micro-organisms. | 0:56:41 | 0:56:46 | |
They finally release the goodness back into the soil | 0:56:46 | 0:56:49 | |
so that new organic life can grow. | 0:56:49 | 0:56:51 | |
Composting is happening all around us in the natural world. | 0:56:57 | 0:57:02 | |
I'm taking the Rot Box Detectives out to see if we can find some. | 0:57:02 | 0:57:06 | |
Now, over here...is what I like to see. A bit of decaying wood. | 0:57:06 | 0:57:12 | |
Now, look at this, this is fantastic. | 0:57:13 | 0:57:16 | |
Now, this is a brilliant habitat for all kinds of stuff. | 0:57:16 | 0:57:20 | |
This was once a piece of a tree. | 0:57:20 | 0:57:22 | |
Obviously, it's fallen off | 0:57:22 | 0:57:24 | |
and the whole of the wood is being eaten away, | 0:57:24 | 0:57:27 | |
transformed into just... | 0:57:27 | 0:57:29 | |
Look at that. It's all breaking down. | 0:57:29 | 0:57:31 | |
The thing I love about decaying wood is it has a wonderful smell. | 0:57:33 | 0:57:37 | |
Absolutely gorgeous. | 0:57:41 | 0:57:43 | |
The whole of the wood is being eaten away, | 0:57:45 | 0:57:48 | |
transformed into just... Look at that. | 0:57:48 | 0:57:50 | |
It's exactly the same process that we saw earlier. | 0:57:50 | 0:57:53 | |
It's recycling on a grand scale. | 0:57:53 | 0:57:55 | |
Composting is nature's wonderful way of recycling. | 0:58:01 | 0:58:05 | |
Plant and vegetable matter are gradually broken down. | 0:58:05 | 0:58:09 | |
First, by larger organisms like snails, slugs, worms | 0:58:10 | 0:58:13 | |
and woodlice, then by ever-smaller micro-organisms and bacteria. | 0:58:13 | 0:58:19 | |
This process can be speeded up by breaking down the organic matter | 0:58:20 | 0:58:24 | |
into small pieces, using machines. | 0:58:24 | 0:58:28 | |
The end result is beautiful compost, | 0:58:28 | 0:58:30 | |
full of goodness, ready to feed more plants | 0:58:30 | 0:58:34 | |
so that the whole process of life and growth can begin again. | 0:58:34 | 0:58:38 | |
Subtitles by Red Bee Media Ltd | 0:58:58 | 0:59:01 | |
E-mail [email protected] | 0:59:01 | 0:59:04 |