0:00:02 > 0:00:04# Wormy fish-killers Convoys of caterpillars
0:00:04 > 0:00:06- # Super-clever, brainless slime - Ugh!
0:00:06 > 0:00:08# Bunny rabbit swarms Wedding storms
0:00:08 > 0:00:10# And pigs that swim at dinner time
0:00:10 > 0:00:13# Tornadoes of fire Starfish going haywire
0:00:13 > 0:00:15- # Algae balls from space - What?!
0:00:15 > 0:00:17# Prairie dogs that chat Birds going splat
0:00:17 > 0:00:19# And fish slapping in your face
0:00:19 > 0:00:21# They're wild and weird Wild and weird
0:00:21 > 0:00:23# Really, really wild and really, really weird
0:00:23 > 0:00:26# They're wild and weird Wild and weird
0:00:26 > 0:00:29# They're really, really wild and really, really wild and weird. #
0:00:29 > 0:00:31On today's spook-tacular show...
0:00:31 > 0:00:33Brainless bats.
0:00:33 > 0:00:35I couldn't believe what I saw.
0:00:35 > 0:00:36Zombie starfish!
0:00:36 > 0:00:39They've been filmed actually pulling off their own arms.
0:00:39 > 0:00:41And a waterfall that bleeds?
0:00:52 > 0:00:54A package has arrived for you, Tim.
0:00:54 > 0:00:56Dangly things, check.
0:00:56 > 0:00:58Cobwebs, check.
0:00:58 > 0:00:59Spiders, check.
0:00:59 > 0:01:01Ooh, yes.
0:01:01 > 0:01:03Mmm. Spooky snacks, check.
0:01:03 > 0:01:06- Oh!- Oh, I like what you've done with the place.
0:01:06 > 0:01:08- Is that for me?- Yeah.
0:01:08 > 0:01:09Just arrived. What is it?
0:01:09 > 0:01:11This is my consignment of toy bats.
0:01:11 > 0:01:13Ah. HE LAUGHS
0:01:13 > 0:01:16- Really finish of the place.- Yeah.
0:01:16 > 0:01:17- That's strange.- What is it?
0:01:17 > 0:01:19Well, it's got no head.
0:01:19 > 0:01:21I'm sure they had heads when I ordered them.
0:01:21 > 0:01:23That's very realistic, though.
0:01:23 > 0:01:24- Realistic?- Mm.
0:01:24 > 0:01:27Who's ever heard of a headless bat?
0:01:27 > 0:01:30Tim, you might want to sit down for this.
0:01:31 > 0:01:35SPOOKY MUSIC
0:01:35 > 0:01:38The Bukk Mountains in northern Hungary.
0:01:38 > 0:01:41Bats were discovered in a cave with their brains removed.
0:01:41 > 0:01:43Ugh.
0:01:43 > 0:01:46Local naturalist Peter Estok had heard a grisly story
0:01:46 > 0:01:49that pointed to an unlikely culprit.
0:01:49 > 0:01:54I was very surprised and I could not really believe that story.
0:01:54 > 0:01:59So we came to the cave and see it for ourselves.
0:01:59 > 0:02:02# Where's your head a-at?
0:02:02 > 0:02:04# Where's your head at? #
0:02:04 > 0:02:05Ugh.
0:02:05 > 0:02:10It's usually birds of prey like hawks and owls which go for bats
0:02:10 > 0:02:13but what Peter discovered went against all his expectations.
0:02:13 > 0:02:16- A ghost?- No.- A zombie?- No.- Dracula?
0:02:16 > 0:02:18- A mummy? A unicorn? - SHE SIGHS
0:02:18 > 0:02:20- Goblins?- No.- Werewolves?
0:02:20 > 0:02:23None of them because they don't exist.
0:02:23 > 0:02:24Oh, what then?
0:02:27 > 0:02:30Peter found a bird in the gloom
0:02:30 > 0:02:32but this was no bird of prey.
0:02:33 > 0:02:37Suddenly a tit, a great tit, entered the cave
0:02:37 > 0:02:42and it was looking for something near the crevices.
0:02:43 > 0:02:46- Great tits? In caves?- Mm-hm.
0:02:46 > 0:02:47Surely they're not to blame, are they?
0:02:49 > 0:02:53You're right, Tim. We're more used to seeing them in our gardens.
0:02:53 > 0:02:56When they're not feeding on nuts and seeds at the bird table,
0:02:56 > 0:02:59the largest prey they're likely to dine out on
0:02:59 > 0:03:02are small insects and spiders.
0:03:02 > 0:03:06But these great tits weren't searching for creepy crawlies.
0:03:08 > 0:03:13We observed that the tits got a bat in its beak
0:03:13 > 0:03:17and it started to eat the bat.
0:03:17 > 0:03:22# Why did we have to meet On the night I lost my head...? #
0:03:22 > 0:03:26And as Peter observed, this wasn't just an unfortunate one-off.
0:03:26 > 0:03:27HE GASPS
0:03:27 > 0:03:30# I guess I just lost my head
0:03:30 > 0:03:33# I know I should really know much better. #
0:03:33 > 0:03:35We saw several occasions
0:03:35 > 0:03:39when great tits managed to get bats
0:03:39 > 0:03:42and they were eating the bats.
0:03:42 > 0:03:45Some of them were still alive.
0:03:45 > 0:03:47No. I'm not buying it.
0:03:47 > 0:03:50What could turn this sweet little great tit
0:03:50 > 0:03:52into a vicious, bat-hunting killer?
0:03:52 > 0:03:54Well, it's not the first time
0:03:54 > 0:03:57great tits have done some pretty strange things.
0:03:57 > 0:03:59- Milk?- Ooh.
0:04:03 > 0:04:05- That was a clue.- Ooh.
0:04:05 > 0:04:08- A tasty one, though. - SHE SIGHS
0:04:08 > 0:04:11HE SLURPS
0:04:11 > 0:04:12Aah.
0:04:12 > 0:04:16Back in the day when milk was delivered to our doorsteps,
0:04:16 > 0:04:19great tits learned how to peck through the foil
0:04:19 > 0:04:22to get to the rich cream at the top.
0:04:22 > 0:04:23Something completely out of the ordinary
0:04:23 > 0:04:25in terms of their usual diet
0:04:25 > 0:04:30but they did it in times of hardship when food was scarce.
0:04:32 > 0:04:35Peter thinks the same thing was happening back at the cave.
0:04:35 > 0:04:41In hard winters it is difficult for the great tits to find food outside,
0:04:41 > 0:04:44especially when the snow cover is significant.
0:04:44 > 0:04:47So, the great tits were starving.
0:04:47 > 0:04:50As soon as Peter put out an alternative source of food,
0:04:50 > 0:04:53they stopped hunting the bats straightaway.
0:04:55 > 0:04:57- Ah, that explains these, then.- Mm.
0:04:57 > 0:04:59Yeah, I don't really want them any more.
0:04:59 > 0:05:02I'll send them back. Refund.
0:05:02 > 0:05:04You really know how to put a guy on edge, don't you?
0:05:04 > 0:05:06Oh, I am only just getting started.
0:05:06 > 0:05:09You see, great tits aren't the only species to track down
0:05:09 > 0:05:11and eat things out of the ordinary.
0:05:11 > 0:05:13- No?- No.
0:05:14 > 0:05:18Over in the States, a couple caught this vegetarian on camera.
0:05:18 > 0:05:20He's got a bird.
0:05:20 > 0:05:22On the ground, Michael.
0:05:22 > 0:05:24Yeah, there's a bird on the ground.
0:05:24 > 0:05:25It's hurt.
0:05:25 > 0:05:29The culprit is a white-tailed deer, munching on a chick.
0:05:29 > 0:05:30What?!
0:05:30 > 0:05:32He's got it in his mouth.
0:05:32 > 0:05:34He's got the bird in his mouth.
0:05:36 > 0:05:39Oh, my goodness. He ate a bird.
0:05:39 > 0:05:42Michael, he ate a bird!
0:05:42 > 0:05:44He ate a bird!
0:05:44 > 0:05:46- Did you see that?- Yeah.
0:05:46 > 0:05:49AMERICAN ACCENT: Tim, he ate a bird.
0:05:49 > 0:05:51Did you see that?
0:05:51 > 0:05:53That's not something you see everyday.
0:05:53 > 0:05:54- Question, though.- Go on.
0:05:54 > 0:05:56Why?!
0:05:56 > 0:05:58Well...
0:05:58 > 0:06:01The boffins think it was either supplementing its diet
0:06:01 > 0:06:04with a quick protein-rich meal
0:06:04 > 0:06:07or trying to get the calcium it needs to grow strong antlers.
0:06:07 > 0:06:10Either way, it's pretty terrifying.
0:06:14 > 0:06:17Deer eating birds, birds eating bats, the world has gone mad.
0:06:17 > 0:06:19It is going to be hard to top that.
0:06:19 > 0:06:21Oh, I don't know.
0:06:21 > 0:06:23I've got a story that will make your toes curl...
0:06:23 > 0:06:25and fall off.
0:06:25 > 0:06:26What?
0:06:26 > 0:06:28Oh, nothing. Get a load of this.
0:06:30 > 0:06:33The West Coast of America.
0:06:33 > 0:06:36Starfish, or sea stars as they're known these days,
0:06:36 > 0:06:38usually live a quiet life.
0:06:38 > 0:06:42Protected by their hard skeleton, they have very few predators
0:06:42 > 0:06:45and spend most of their time mooching around rock pools and reefs
0:06:45 > 0:06:47eating shellfish.
0:06:47 > 0:06:50Oh, they're so pretty.
0:06:50 > 0:06:52- Do you mind?- Sorry.
0:06:52 > 0:06:57But in 2013, divers noticed something very disturbing -
0:06:57 > 0:07:01thousands of sea stars disintegrating and dying,
0:07:01 > 0:07:04their limbs littering the seabed along the whole Pacific Coast.
0:07:04 > 0:07:07- Whoa!- Yeah.
0:07:07 > 0:07:10Melissa Redfield from the University of California in Santa Cruz
0:07:10 > 0:07:13witnessed first-hand exactly what was going on.
0:07:17 > 0:07:19- SHE GASPS - Cool, isn't it?
0:07:19 > 0:07:22No! It's terrifying!
0:07:22 > 0:07:28People have seen arms basically crawling away from the body.
0:07:28 > 0:07:30- What?- I know.
0:07:31 > 0:07:34And if that's not enough, once they're detached,
0:07:34 > 0:07:37the limbs seem to have a life of their own.
0:07:37 > 0:07:40They're moving like zombies. Ugh!
0:07:40 > 0:07:42Sea stars losing their arms all over the place
0:07:42 > 0:07:44and crawling away is pretty terrifying.
0:07:47 > 0:07:50If you imagine that that was some sort of animal on land,
0:07:50 > 0:07:52losing its arm and crawling away,
0:07:52 > 0:07:55you know, it would be quite frightening and a lot more obvious.
0:07:57 > 0:07:58Oh, there's a...
0:07:58 > 0:08:01HE LAUGHS Oh, Tim!
0:08:01 > 0:08:03Don't worry, it's armless.
0:08:03 > 0:08:05It's not going to arm you.
0:08:05 > 0:08:07Because it's...
0:08:07 > 0:08:10- Oh, no. I'm out. - Just going out on a limb here...
0:08:10 > 0:08:12Oh, should have thought of that.
0:08:12 > 0:08:15..but once they've lost them, can't they re-grow them?
0:08:15 > 0:08:17You are right.
0:08:19 > 0:08:22If one of their limbs is nabbed by a predator,
0:08:22 > 0:08:24they can simply re-grow a new one.
0:08:24 > 0:08:29In fact, they can lose up to 3/4 of their own body and still survive.
0:08:29 > 0:08:32Even if they get it wrong sometimes.
0:08:32 > 0:08:34That arm is massive.
0:08:34 > 0:08:37- It's not growing a new arm.- No?
0:08:37 > 0:08:39It's growing a new body from an arm.
0:08:39 > 0:08:42- Whoa!- I know.
0:08:42 > 0:08:43And it's all possible as long as
0:08:43 > 0:08:47a small portion of the central disc remains.
0:08:48 > 0:08:51But this doesn't explain the strange phenomenon
0:08:51 > 0:08:53on the West Coast of America.
0:08:53 > 0:08:57These starfish are dropping their arms with no sign of danger nearby.
0:08:57 > 0:09:00So, what's happened to these adorable invertebrates
0:09:00 > 0:09:03and turned them into the walking dead?
0:09:03 > 0:09:07Well, in November 2014, biologists found the culprit.
0:09:08 > 0:09:12The zombie-like behaviour is all down to a virus
0:09:12 > 0:09:16aptly named sea star-associated densovirus.
0:09:16 > 0:09:17Catchy.
0:09:17 > 0:09:20Yeah. Actually, it's very catchy.
0:09:20 > 0:09:21It's spreading like wildfire
0:09:21 > 0:09:24and it's that that's making their limbs fall off.
0:09:24 > 0:09:27So what is going to happen to the sea stars?
0:09:27 > 0:09:31Well, there is a little glimmer of hope, Naomi.
0:09:31 > 0:09:33We do have a little glimmer of hope
0:09:33 > 0:09:35which is that this past spring and summer,
0:09:35 > 0:09:38we have seen a big influx of juveniles.
0:09:38 > 0:09:41This is likely because when many animals are stressed,
0:09:41 > 0:09:45as a sort of last ditch effort to keep the population going,
0:09:45 > 0:09:46they'll reproduce.
0:09:50 > 0:09:53Sea creatures with their arms dropping off, fair play, Tim.
0:09:53 > 0:09:55- That was a good story.- Thank you.
0:09:55 > 0:09:58HE SCREAMS
0:09:58 > 0:09:59You thought that was scary,
0:09:59 > 0:10:03consider it just a warm-up to a very chilling finale.
0:10:03 > 0:10:04You gave me zombie sea stars,
0:10:04 > 0:10:08I give you a frozen waterfall of blood.
0:10:08 > 0:10:12Mwah-ha-ha-ha-ha!
0:10:14 > 0:10:19Antarctica, a remote, frozen wilderness
0:10:19 > 0:10:25and hidden away in this world of white is a gaping wound in the ice.
0:10:25 > 0:10:28This is Blood Falls.
0:10:28 > 0:10:32- Is that lump of ice bleeding? - Uh-huh.
0:10:32 > 0:10:33It's a bizarre mystery
0:10:33 > 0:10:36that's intrigued scientists for more than a century
0:10:36 > 0:10:40and for one it became a lifelong fascination.
0:10:40 > 0:10:44The first time I saw Blood Falls was in a graduate glaciology class
0:10:44 > 0:10:47and I saw a picture of it and I got really excited and intrigued
0:10:47 > 0:10:49as to what this feature was.
0:10:49 > 0:10:53Everybody thought the incredible spectacle was down to a phenomenon
0:10:53 > 0:10:55called watermelon snow.
0:10:55 > 0:10:58Wait. Wait a second. Watermelon snow?
0:10:58 > 0:11:01- Yeah.- That sounds amazing.
0:11:01 > 0:11:03HARP PLAYS
0:11:06 > 0:11:08Ah!
0:11:08 > 0:11:09Ah! Ah!
0:11:09 > 0:11:10Oh.
0:11:10 > 0:11:12- Ah. - HARP PLAYS
0:11:12 > 0:11:14Ooh, and painful.
0:11:14 > 0:11:16What are you on about, Tim?
0:11:16 > 0:11:18This is watermelon snow.
0:11:20 > 0:11:25Watermelon snow is caused by algae which grow at low temperatures.
0:11:25 > 0:11:29The algae produce a pigment that acts as a natural sunscreen
0:11:29 > 0:11:32and it's this pigment that gives the snow a pink appearance
0:11:32 > 0:11:34and the faint smell of watermelon.
0:11:34 > 0:11:35Hence the name.
0:11:35 > 0:11:40# I just like it nice and juicy Watermelon man... #
0:11:40 > 0:11:43Well, that's it then. Case solved.
0:11:43 > 0:11:46Watermelon snow. It's not scary, it's delicious.
0:11:46 > 0:11:49Er, actually, no. Case not solved.
0:11:49 > 0:11:52- Oh, really?- Hmm.- So what is the cause of the bleeding waterfall?
0:11:52 > 0:11:53Glad you asked.
0:11:55 > 0:11:56Where did you get that?
0:11:56 > 0:11:58Oh. Shwoo-ponk.
0:12:00 > 0:12:02Mmm.
0:12:04 > 0:12:05Hmm?
0:12:05 > 0:12:09Jill discovered a vast reservoir of salty water
0:12:09 > 0:12:13stretching at least 5km beneath the glacier.
0:12:13 > 0:12:16And in there, she found something extraordinary.
0:12:16 > 0:12:18HE SLURPS
0:12:18 > 0:12:20- A giant watermelon?- No.
0:12:20 > 0:12:21A tap-dancing polar bear?
0:12:21 > 0:12:23- No.- A swarm of jelly babies?
0:12:23 > 0:12:25- No... What?- Yeah.
0:12:25 > 0:12:27Jelly babies, man, they are scary.
0:12:27 > 0:12:30It's like a baby but made of jelly.
0:12:30 > 0:12:33I mean, who on Earth would want to eat an effigy of a small child?
0:12:33 > 0:12:34That is just wrong.
0:12:35 > 0:12:37Ooh.
0:12:40 > 0:12:44Gill discovered a massive community of bacteria...
0:12:44 > 0:12:46That would have been my next guess.
0:12:46 > 0:12:51..frozen, deprived of oxygen and isolated for millions of years.
0:12:51 > 0:12:53That still doesn't answer why the waterfall is red.
0:12:53 > 0:12:55Well, without oxygen to breathe,
0:12:55 > 0:12:58these ingenious little life forms evolved a way
0:12:58 > 0:12:59to live off elements in the rock,
0:12:59 > 0:13:04extracting minerals like iron to produce energy.
0:13:04 > 0:13:07And guess what colour iron is when it dissolves in water.
0:13:07 > 0:13:09- Blue.- Red!- Red.
0:13:09 > 0:13:10- Got it in one.- Or two.
0:13:10 > 0:13:13Mystery of Blood Falls solved.
0:13:13 > 0:13:15So it's basically rust not blood?
0:13:15 > 0:13:17- Yes.- Well, that wasn't scary at all.
0:13:17 > 0:13:19Well, I must say, Tim, I'm impressed.
0:13:19 > 0:13:21- You dealt with that very well. - Thanks.
0:13:21 > 0:13:25Well, it's just over the years now, I've changed as a person.
0:13:25 > 0:13:27I've become more mature, more sophisticated,
0:13:27 > 0:13:28I've become a lot braver.
0:13:28 > 0:13:31Well, that's good because I've brought you a little Halloween gift.
0:13:31 > 0:13:35- Aw.- And to be honest, I wasn't sure quite how you'd handle it.
0:13:35 > 0:13:36Wow, it smells amazing.
0:13:36 > 0:13:37Is it aftershave?
0:13:37 > 0:13:39# Sticky, sticky, sticky, sticky jelly... #
0:13:39 > 0:13:41HE SCREAMS
0:13:41 > 0:13:44# Easy as jelly, baby. #
0:13:44 > 0:13:46See you next time. Bye.
0:13:46 > 0:13:48Bye-bye.
0:13:51 > 0:13:53Please don't eat me.
0:13:53 > 0:13:56# They're wild and weird Wild and weird
0:13:56 > 0:13:58# Really, really wild and really, really weird
0:13:58 > 0:14:00# They're wild and weird Wild and weird
0:14:00 > 0:14:06# They're really, really wild and really, really wild and weird
0:14:07 > 0:14:11# Wild and weird! #