Episode 4 Nature's Weirdest Events

No matter how well we think we know our planet, the natural world still

has the ability to surprise us, to shock us and to maybe sometimes even

to scare us. With its extraordinary events and bizarre behaviour. New

technology means that nature's weirdest phenomenon are being caught

Evermore readily on camera. So we're going to bring you the strangest

stories our world has to offer. I've never seen anything like that

before. From bizarre body snatchers. And a butterfly blizzard. Do you see

that, guys? With the help of scientists, experts and eyewitnesses

we're going to try and unravel exactly what on earth is going on.

So let's get cracking. First up, we reveal some astonishing super

powers, specialist skills that help animals succeed in the toughest of

environments. Our next group of extreme jet-setters proof when it

comes to super powers, size isn't everything. In early October 2011

the Denning family were hiking through woodland in central Mexico.

When they became part of one of the most extraordinary events in the

natural world. Look at them all. Do you see that, guys? Millions of

butterflies. A vision in orange. Carpeting small stands of pines.

This is awesome! They were at the centre of a butterfly blizzard.

Butterflies in their millions that descend on certain areas of trees in

Mexico and California like clockwork every year. Days before these trees

would have been bare. So where have all of these swathes of better flies

come from and why are they here? They can be found throughout the

United States where ever their staple food, milkweed is flentyful.

This food source can take them as far north as Canada. Which, when the

seasons change, can be a brutal place for a butterfly. Richard Fox

has spent years studying the intricacies of butterfly behaviour.

Basically, it's too cold in the winter time across most of the

United States and certainly in Canada for these butterflies to

survive. They have to move or die. The monarchs are flying for their

lives away from the cold north. But to reach these warm winter hideouts,

well that's a seriously long-haul flight. These butterflies cover over

2,000 miles. They fly for anything up to 10 weeks to reach these winter

roosts. It's the kind of journey usually undertaken by birds or great

herds of mammals. So how does a tiny insect manage it? Well, these are

butterflies with super powers. We tend to think of butterflies as

delicate creatures blown around by the wind. These monarchs are serious

flying machines. They have the brain the side size of a pinhead, yet they

can navigate across a continent. They can fly at high altitude.

People have seen them from aeroplane windows. They are not flying blind.

Monarchs come equipped with some serious inbuilt GPS. They have a

time serious inbuilt GPS. They have a

working out north and south. In their ant ten nigh, their feelers,

they have a clock which enables them to take account for the passage of

the sun across the sky -- antennae. As they travel south the millions of

monarchs from all over the United States are funneled together by the

Gulf coast and the rocky mountains. In a good year, it might be 150

million monarchs. Rather than spread throughout the forest, they huddle

close together, warmth in numbers against the cooler nights. But as

the sunrises, and the day heats up, the butterflies leave the branches

in an orange explosion. Not surprisingly, these winter

roosts have become tourist hotspots. For the people that live in these

special areas, the arrival of the monarchs is cause for celebration.

Lowry is the director of the The museum of Natural History in Pacific

Groove California. Also known as Butterfly Town, USA. Pacific Groove

takes its monarchs very seriously. -- Crove. All the school children

gather together to welcome the monarchs back to the town. The

butterflies are the cultural icon of this town. Just how they find the

exact spot that their family member travelled to the year before is

still not fully understood. Nor is why they choose these particular

stands of trees. When it comes to these extraordinary migrators, there

are still more super powers left to be discovered. That monarch

migration is truly remarkable. Did you know that you can witness a

similar effort in the UK. Painted ladies end up in our gardens. We

used to think they died here. Recently, however, we have spotted

them flying back to Africa. When you take in all of the generations,

that's a round trip of more than 9,000 miles. Not bad for an insect

that weighs less than a gram. This next strange substance is unlikely

to win any popularity contests. It there is a very sticky situation

facing fishermen in the Atlantic. How do you get rid of all that

slime? They are pulling up their nets and pods to find them covered

in slime. Does it ruin... An ooze is clogging their nets and having to be

bailed from boats. Oh. Armfuls of this colourless gloom is appearing

any one catch. With often more slime than fish, removing it from a haul

is an absolute nightmare. Now, it's too common a complaint to be

attributed to some freak event or rare natural phenomenon. Something

is creating enough of this substance to drive fishermen crazy. The

question is - what? Well, the source of this mystery mucus can be found

on the deep sea floor. The perpetrator is the hagfish. It's the

undertaker of the deep, searching the murky bed for corpses. It uses a

tongue to pull flesh from bone. It will even wriggle inside a rotting

corpse to Dee row the soft flesh under the skin -- devour. Literally,

eating the victim inside out. Nasty eating habits aside, the question

remains - why would a creature that lives on the seabed need to produce

slime? Well, aside from its willingness to eat sea floor scraps,

the hagfish doesn't seem to have very much going for. It's pretty

much blind, has no jaws or tough scales, it looks vulnerable. But, in

fact, the hagfish really is quite a success story. It's been around for

a whopping 300 million years, which makes it one of the oldest fishes in

the sea. The secret to its success is slime. It's a defensive strategy

so brilliant that it makes the hagfish quite literally,

untouchable. Professor Doug Fudge studies these master slimers. So the

hag fish is essentially covered with slime glands. The when an animal is

attacked by a predator there is muscle in the area where it's

touched that cause those slime glands to release their contents.

There is actually a little mini volume cape be owe of slime that

comes out of the gland. It's reinforced with tens of thousands of

silk-like protein fibres we call slime treads. It mixes with sea

water and forms this large volume of very unusual fibre reinforced slime.

A single hagfish can turn a bucket of water into slime in seconds. That

is so gross. It is proves to be a pretty fantastic under water weapon.

In a recent study, that was published by a group in New Zealand,

they showed hagfish using their slime in a wild situation. The mucus

is designed to choke a predator by clogging up its airways much the

shark is left gagging as its gills fill with mucus. Every assayant is

repulsed by a wall of slime. Is -- assailant. The technique is

effective that thehag fish is unpreterribled. How does the hagfish

prevent itself from becoming the victim of its own slimy strategy?

They have a way of getting out of the slime. They will tie their body

in a knot and then they'll pass their body through the knot and that

will wipe the slime off of their body. A necessary skill for the

ocean's most slippery character. Now, you may not like this, but

humans produce slime too. In the form of snot. What's remarkable is

that hagflush slimed and human snot are composed of similar proteins. --

hagfish. Humans use their snot to trap harmful substances and expel

them from the body. When you think about it, hag fish and humans are

using slime as a frontline defence. These animals have proved that in

the natural world, it pays to be a master craftsman. Whether you are a

silk spinner, escaping the rising tide, a slime producer, defending

yourself from attack, or a sand sculptor, looking for love. A super

structure is crucial to success. So a specialist skill with help an

animal get ahead. What if you can't survive on your own? Rather than

admit defeat, this next selection of weirdness shows enlisting some help

can hold the key. There is a strange subterranean structure created by

remarkable team work. But first a chilling tale of some real-life

zombies. Eric Williams from Delaware was mopping his kitchen floor when a

dead beetle began to mutate in front of his eyes. From its body something

long and worm-like was emerging. Eric wasn't the only one to witness

this miniature horror. No idea what those things are. I see all these

strange hairs moving around. What do you think that is? It's a cockroach.

Look at the stringy bit coming out of it. All the records had one thing

in come, a mopped floor or nearby puddle, the presence of water was

triggering these writhing worms. That's disgusting. But what were

they and how had they got into the bodies of these insects?

Biologist Janice Moore has spent a lifetime fascinated by this

particular weird event. Whenever I was a child I'd used to see these

long worms squiggle in around at my grandfather's. I was told they were

horsehair worms and that is a common name because legend says that these

worms come from horsehair. In reality, they are parasites. These

parasites live inside say the cricket and grow up to be huge

compared to the cricket, all called up. The cricket is almost total

parasite. The hare worm lover develops inside the body but it has

to breed and to do that it has to find water. -- the hare worm lava.

It has no qualms about making the lava do all of the legwork. The

cricket becomes almost suicidally attracted to water and they have

been reported to jump into toilets, into dog water bowls. And if the

hairworm is big enough, the merest hint of moisture could be enough to

tempt it out. I have never seen anything like that before. Keep an

eye out for these miniature body snatchers because they are found

here in the UK as well. In fact, in every corner of the globe, super

sneaky parasite species have found ways to get the others to do the

hard work for them. For example, the mind control that lurks in German

gardens. There is a parasite which lives inside the intestinal tract of

a variety of songbirds. The parasitic flatworm reaches materia

tea inside the digestive system of the bird and casts out its eggs in

the bird's droppings. This would be the end of the cycle if it were not

for the garden snail that finds bird droppings irresistible. When the

these eggs, the egg hatches and a little larval parasite, a flatworm,

moves in and there it grows up into a striped Mass. The snail's tentacle

is now one enormous a striped Mass. The snail's tentacle

flatworm brood sack. But a striped Mass. The snail's tentacle

parasitic mastermind encounters a problem. Just like the hairworm

cannot breed inside the snail. Delay problem. Just like the hairworm

its eggs it has to be once again inside a bird's intestinal tract.

How does the flatworm complete the cycle? Mind control. It forces the

usually reclusive snail upward towards the light. Once exposed, the

snail's tentacle is a pulsates in Grub on a plate. Birds will look at

snail's tentacle is a pulsates in they will eat it. And in that way

the life cycle is complete. Now, the poor snail is

the life cycle is complete. Now, the might just get out alive minus

tentacle. But other hosts are not so lucky. Our next parasite requires

its host to make the ultimate sacrifice. So one of the most

spectacular examples of zombie behaviour is and is infected with

fungus. If you're battling for space in the rainforest, hitching a ride

on the back of an angled would seem to be a clever tactic. -- the back

of an ant. It is not clever enough for the type of fungus. The fungus

enters the body through the and's windpipe, where it begins to extract

nutrients from all but its major organs. As the fungus grows, it eats

the ant alive, while leaving it with just enough of its faculties to

move. The reason why it does this is brilliantly devious. To cast

spores, the fungus needs to be high, so it floods the and's brain with

chemicals, forcing it on an upward march. Having reached an optimum

height, the ant has served its purpose and called to set devours

its brain, before with a final flourish it bursts through the

exoskeleton and casts spores into the air. Does a wonderful story if

you happen to be reading about it and a really nasty story if you an

ant. One of my favourite types of body

snatchers actually lives in UK waters. The larvae of a tapeworm in

his boots the stickleback. -- inhibits the stickleback.

It does not leap out of the mouth of a stickleback into the mouth of a

passing bird. It modifies the behaviour causing it to flip over

onto its back revealing its bright white belly making it far more

obvious to predators like herons. I know it is a sad end for the old

stickleback, but you have to admit when it comes to parasites, mind

control is a fiendishly effective survival technique.

Bending the will of others for your own game is not the most altruistic

of survival methods. Thankfully, our next story shows what can be

achieved if you choose to work together. In May 2004, a group of

scientists gathered in South America, at a very particular spot

in rural Brazil. They took up tools and began to dig. Over the next few

days, they painstakingly excavated the area. And from the soil,

something incredible began to emerge. They uncovered a vast

network. Some 50 metres squared. An architectural maze of different

shapes and structures, branching out into the ground. This subterranean

design was precise and too complex to be created by chance. It had been

engineered. But by what? What could have created this underground

architecture? What the scientists had uncovered

was a secret city. A giant home created for some of the smallest

animals on the planet. Ants. And for and biologists like Ross Kirby, this

experiment brought Deary to life. This is the first time that we can

literally see the bare-bones of what they have built. We poured cement

into the empty nest of leafcutter ants. Once the cement had set we

could reveal the underground metropolis. This was not your

average and nest. This was an entire and city, going as deep as eight

metres into the ground. And masterminded by a population of up

to 7 million leafcutter ants. But why does an ant need such an

impressively conduct home? There are chambers which are important where

the eggs develop. There are waste disposal chambers. There are also

many different tunnels, not just to take the ants from chamber to

chamber, but to allow air to be completely circulated throughout the

nest. And used pheromones to organise construction work and to

guide them from foraging sites. These chemical trails help them to

work efficiently and stop them from getting lost. They ensure a steady

steam of -- stream of grass into the nest. But it is not to eat. The

ands cannot digestive grass. They use the blade to feed a fungus,

cultivated in special garden chambers. This fungus is the ant's

preferred main meal. That is a lot of fungus farming. A nest needs to

be this size to support such a large colony. But it is almost

inconceivable that something as small and simple as an ant could

have created such an amazing structure. When looking at an entire

ant colony, you should not be looking at it as 7 million

individuals, you should look at it is one great collective unit. A

single ant by itself is not up to much. When you have 7 million of

them interacting together, their behaviour can be quite complex. All

of these ants working together for the good of the whole colony,

transform from individuals into a single living being. A super

organism. One brain, 7 million ants strong. It is this organisation that

makes one of the smallest animals capable of such incredible

engineering. So clearly, being part of a super

organism is beneficial. But a group mentality can also have its

drawbacks. One woman travelling through Peru in

2008 came across some ants behaving strangely. They were spinning round

and around in a constant circle. One by one they began to collapse and

die. She was not the only person to witness these peculiar death

circles. Why were they on self-destruct? It is most likely

that these ants were out foraging when they got separated from the

rest of their party. With the pheromone trail lost, they began to

panic and follow each other's pheromones. This confused game

follow my leader forced them into a never-ending circle. And because

ants are not programmed to think like individuals, they did not save

themselves. Instead, the circle became tighter and faster until the

ants simply died of exhaustion. Thankfully, these ant death circles

are relatively rare events, clearly proving that the benefits of

teamwork must outweigh the potential for disaster. Ants are not the only

organisms which forms super organisms. Take bees, for example.

For high to be successful, thousands of bee brains must work together.

The benefits are security, bed and board. When it comes to super

organisms, great minds must think alike.

These stories show the importance of a listing some help. Whether it is a

devious parasite control and a host against its will or an ant colony

combining forces to build a subterranean met the Acropolis --

mega droplets. Two brains or seven if you can manage it, are better

than one. So there we are, we have delved into

a catalogue of the most fun, the most foul, the most morbid and

marvellous stories our planet has two offer. Whether it has been

bizarre animal behaviour or weird natural phenomena, it has had the

very best of our brains completely baffled. But then given the natural

world's ability to astound, it leaves us with one final and

inevitable question, what next? MUSIC: Boombastic

by Shaggy