Original subtitles

Let's face it, our world is downright weird.

Oh!

Crawling with creatures you've never heard of...

I can't believe that's a living thing.

..full of the unexpected...

..like freak weather exploding out of the blue...

I thought I was going to die.

..and rocks that spontaneously combust...

I thought it was dynamite going off.

..and the unexplained.

An unborn twin, discovered inside a brain.

There was multiple hair follicles, bone and teeth.

We scoured the globe to bring you the very weirdest stories.

Ah!

I could feel this intense pain,

as if you were being stabbed by hundreds of syringes.

In this series, we're going to examine the evidence,

test the science and unravel the mysteries.

We're going to discover what in the weird world is going on?

In this episode, we'll uncover the secrets

to some of the natural world's weirdest mysteries.

How could the sun's rays exterminate birds in flight?

And why have these monkeys become trained in first aid?

Exactly how do you get spider silk from a goat?

And how far would a porcupine go, to find true love?

Well, it all starts here.

Nevada, long-time home of the weird.

You know, for decades, this place has been home to unexplained

sightings, bizarre conspiracy theories.

But in 2013, something every bit as weird,

but very real, happened in the skies here.

A local photographer captured these strange explosions.

I saw these objects going across the frame of the video.

Sometimes they would change direction, sometimes they'd

go up, sometimes they'd go down and I didn't know, at first,

what they were.

Sometimes they would dive down,

maybe like it was trying to escape from something.

Sometimes it would turn around and go in the other direction.

So, what were they?

What was going on?

It was clearly too early in the day for fireworks.

Military testing, perhaps?

I examined the videos closely and I was able to see a little

flapping motion, which was their little wings were flapping.

Wildlife officials found the bodies of birds,

birds that had fallen to their death from clear skies.

Now, mass bird deaths, although shocking, are not that unusual.

Poisoning and collisions like this plane strike

can bring down flocks of birds.

But the reports from Nevada were different.

They found about 83 different species of birds.

Everything from very small birds like hummingbirds to doves,

to larger birds like ravens, and raptors, like peregrine falcon.

A bizarre collection of different species,

but with one thing in common.

The feathers were sort of melted and they were in fragments.

The birds were all burned alive.

What a gruesome way to go.

What could have caused this?

It's a conundrum worthy of Area 51,

but it is one that can be explained via a quick trip over the pond.

September 2013, central London.

We've had temperatures of up to 50 degrees Celsius

in the last few minutes and if I just look at the current

temperature, well, it's still 42 degrees.

People have been trying to cook eggs.

My colleague realised there was a smoke coming out. He smelt it.

We looked back and the carpet was on fire.

Melted bicycles, burned cars...

We realised it was from the big building.

..and all fingers pointed at the building above that was

burning a hot spot on the pavement below it, but how?

Now, we all know that mirrored surfaces reflect sunlight

and when they're curved, they focus this into a central point

where it becomes a much more powerful beam.

That's what was happening with that London tower block.

It was focusing the beam down onto the pavement where it was hot

enough to damage stationary objects.

It's impressive,

but it's still not enough to set fire to birds in flight.

For that, you'd have to seriously upscale.

This isn't a mirage.

This is Ivanpah, a power plant with a difference.

300,000 mirrors reflect the desert sun onto a central tower.

Boiling water to create steam which then generates energy.

It's an undeniably beautiful piece of engineering,

but with an unexpectedly deadly side-effect.

Now, we can demonstrate the power of Ivanpah, right here.

EERIE MUSIC

Ivanpah in miniature.

These tiny mirrors reflect the light.

But, crucially, it's not scattered.

The mirrors are perfectly angled.

It's a parabolic curve focusing the light onto a centre point.

And turbo charging that light and the heat intensity.

Now, it's hot enough to roast wood, even melt lead.

And feathers, well, they simply don't stand a chance.

But that, on an industrial scale,

out here in this desert, under that sun,

the power generated is off the scale.

As the desert sun hits Ivanpah's 300,000 mirrors,

the light is reflected towards the towers,

creating temperatures of up to 1000 degrees Centigrade.

The experiment in green energy had created a solar death ray.

So, what can the plant do, to solve this very sad problem?

They've been willing to modify their software system.

They've also been working to test out deterrent systems to scare

birds away from the danger zone around the towers.

Let's hope they find a solution that works.

So, this tragic loss of avian life is testament to the awesome

power of the sun.

It just makes you wonder, doesn't it,

what else the sun is responsible for?

How about changing the landscape of musical history?

In the 1600s, Antonio Stradivari took a piece of spruce

and made a violin.

Today, his instruments are the most famous on the planet.

Every music collector wants to own one

and every dealer wants to get their hands on one.

When I pick up one of these instruments,

there's always something a bit special and magic about it.

An instrument from the golden period, which this instrument is from,

could be worth from a few million dollars to 12 million dollars

or 15 million dollars and if it's a great one, oh!

142,000, 145,000...

Wow. And their desirability is down to one thing - sound.

It's got a real magic aura to it

and it's partly for that reason that people have tried to figure

out what's the so-called secret of Stradivari.

Yes. For 300 years, craftsmen have tried to discover

the secret to Stradivari's sound.

They've tested every theory.

The wood has been soaked in seawater or the varnish has volcanic ash

in it, was another one I remember.

But they've all failed, until, that is...

..a scandal hit the headlines.

Now, Stradivari's most famous violin is known as the Messiah

and it's aptly named, apparently, because those in the know,

claim that it's the world's ultimate violin.

But back in 1999, someone had the temerity to

suggest that this priceless piece of musical history, wasn't

the real deal, that Stradivari hadn't made it, that it was a fake.

Now, let's just put that in perspective.

That's a bit like saying that Leonardo da Vinci didn't

paint the Mona Lisa, that John Lennon didn't write Imagine.

The classical musos were in absolute uproar.

To calm the clamour,

the Messiah was brought under the scrutiny of a specialist.

It was a thrilling moment, for me, when they took it out of the case.

I have gloves on and they put it in my hands and said,

"Here is a musical instrument worth millions of dollars.

"Do what you want with it."

Henri and his team studied the unique rings of the Messiah's wood.

We use pattern matching in the tree rings sciences, to determine

when these tree rings were formed.

The rings of the Messiah matched perfectly with samples

taken from the Stradivari Forest.

When I saw that, I knew that this was not a fake, it was not a copy.

This was an instrument that was contemporary with

Antonio Stradivarius and in all likelihood,

was made by Antonio Stradivarius.

So, it was the Messiah's wood that gave the world's most famous

violin its ring of authenticity.

But I've got to tell you, that those

rings revealed something far more exciting.

Now, remember I was talking about the sun. Well, stick with me.

Right, we know that every ring represents a year in a tree's life,

but the thickness of each ring is just as important.

A wide ring tells us that during that year,

the tree grew very quickly.

But a thin ring means exactly the opposite.

That means the tree grew slowly.

And the Messiah had incredibly thin rings.

So tightly packed, that the wood was three times more dense

than that of a modern instrument.

Dense enough to create an exceptional sound.

But why was that wood so extraordinarily dense?

And what on earth has the sun got to do with it?

Well, when Stradivari was making violins in the Italian Alps,

the sun was behaving very strangely.

Between 1300 and the late 1800s, its power was reduced.

Lakes froze...

..the days darkened.

It was a little Ice Age.

Now, the Little Ice Age might be news to you

but it actually happened.

In fact, it got so cold during the winter times that the Thames

froze over.

Now, imagine you are a tree growing somewhere in the Alps

but growing quite close to a famous violin maker's house.

You're using every last little bit of that sunshine,

but it's difficult,

which means you're growing very, very slowly indeed.

It's starting to fall into place.

Henry's theory is that the sun, or the lack of it,

created super-dense, super-musical spruce.

So, solar starvation could be the secret for the Stradivarius's

beautiful and unique sound.

But of course, the world's finest violin wouldn't be any good

without the world's finest violin strings.

In 2012, a Japanese researcher decided to produce the world's most

beautiful violin string.

Instead of using the traditional gut or metal,

Dr Osaki wove 15,000 strands of silk.

RADIO TUNING

VIOLIN MUSIC

I know what you're thinking.

You're thinking, "That still sounds like a violin,"

but it's a little bit softer.

RADIO TUNING

And to trained ears...

it's more profound.

Which is downright weird, because Dr Osaki isn't a musician.

He's a medical researcher

and he made the strings with the help of his lab partners.

300 orb web spiders.

Their silk fibres combined together are tough enough to be played.

And Dr Osaki puts the string's unique sound down to the way

the fibres compact together leaving barely any air gaps

between the strands.

It's not really my sort of thing, but I'm growing to like it.

But with 15,000 strands of silk in every single string,

it's unlikely that they're ever going to hit the mass market.

It would be impossible to kit out a fully-fledged orchestra.

Unless, of course, you had a spider silk making factory.

But then, that's a ludicrous idea...

isn't it?

Well, no.

Not for one extraordinary scientist, who's discovered

the secret of spider-silk manufacturing.

Spider silk is the strongest fibre that's found in nature.

Has a tensile strength greater than Kevlar

and has an elasticity or elongation greater than nylon.

So, it means we can use it for different medical

products like artificial ligaments, artificial tendons, hard body parts.

For airplane parts, even for protective clothing.

A silk aeroplane, you'd need tonnes of the stuff.

But Randy's not running a spider sweatshop.

So, the problem with using spider silk from spiders themselves

is the spiders can't be farmed.

They're territorial, they're cannibalistic, so,

if you put a lot of them together, they kill each other until everybody

has enough room, so you've got to come up with

another manufacturing method.

Born and bred in Utah, Randy has farming in his blood.

Goats are his thing and although they might look normal,

these goats are anything but normal.

You see, inside their cells is a little something extra.

Something spidery.

The majority of these goats have a gene in them that came from a spider.

We took the DNA for the spider-silk gene.

That DNA was then injected into an embryo

and we take the embryos and we implant them into a...

into an accepter female and five months later,

she has a baby goat for us.

Real-life spider kids...

..that will grow up to produce spider silk in their milk.

Now, this isn't actually as weird as you might first think

because spider silk, when in the spider, is also a liquid.

But I have to say, this is where the similarity ends,

because spiders have special spinnerets that spin

the liquid into solid lines of silk.

But how do you get silk out of a goat?

So, we take the milk from the goats here.

We take it back to the lab and we purify

the spider-silk protein out of it.

And then we try to mimic what the spider does in terms of actually

making the fibre so we try to spin it

so that we pull it instead of pushing it out.

Then we stretch it, which is exactly the same thing that a spider does.

This year's crop of kids look cute now,

but soon they'll be spider-goat silk-making machines.

So, our very best goat makes about four grams of spider-silk

protein per litre.

She produces about eight litres per day, so about 32 grams per day.

And that's enough to spin 32,000 metres of silk.

And that's the length of 3,000 football pitches.

For now, though, they're more interested in Randy's trousers.

Well, I suppose they're still 99.9% goat after all.

Spider goats.

Sounds like science-fiction.

But if you think that's a weird hybrid, what if I were to

tell you that someone had actually fused spider silk

with human skin?

A lab in the Netherlands took Randy's goat silk

and created Super Skin.

Then they shot at it.

GUNSHOT

So, why bother going to all the trouble?

But look!

The sample isn't destroyed.

Just look at it stretch as the bullet hits.

Incredibly, the spider skin holds that bullet firm.

With the silk strengthening properties, it's

nearly as tough as Kevlar, the stuff used to make bulletproof vests.

It's got real potential for an exciting super-fabric.

Real-life bulletproof spider skin.

What a thought.

So, all in all, solar power has serious implications

for our avian friends, but sun starvation creates sweet sounds...

especially when teamed up with silky strings.

And, you know, a spider goat is, in fact, a very real and very useful

species, whose milk has brought us one step closer to super powers.

OK, what's coming up next?

Well, how do you get from simian CPR to spiny star-crossed lovers?

Let's take a trip to India.

Kanpur train station.

The platform bustling with passengers...

..unaware that they are about to witness a dramatic event...

..as a body falls onto the tracks.

A male macaque has been electrocuted crossing live wires overhead

and there's no sign of life.

But then, something bizarre happens.

Another macaque grabs the body.

Shakes it.

Pummels it.

Bites it.

Even submerges it in water.

For 20 minutes he keeps up this violent cycle.

And then...

to the absolute amazement of the crowd...

..the macaque begins to come round.

Now, unsurprisingly, the film went viral.

Over one million people wanted to watch this monkey CPR.

It's an incredible piece of footage and really weird, too,

because we've come to know that some primates can demonstrate

intelligence, but we don't often think of them

as being truly sympathetic.

But you know, these macaques live in strict hierarchies

and the males will do anything they can to climb up that hierarchy.

So, here's my question.

Is this male really administering first aid or is it taking

advantage of an opportunity?

An opportunity to kick one of its key competitors when it's down?

When it's really down?

Well, amongst the millions of viewers was a macaque specialist.

Here was this macaque that seemed to be performing CPR on this...

on his buddy.

I sent it to my family, I sent it to my friends,

I sent it to other monkey researchers and said, "Have you seen this?

"Have you seen what's happening with these animals in India?"

I knew there had to be more to this story. There had to be a back story.

Lisa got inside the mind of the macaque.

Females stay in a troop from birth to death.

But males, as they reach sexual maturity, actually have to

migrate out.

And they do that typically together

and then they formed kind of these boy bands.

These male bands that are kind of moving throughout the area in search of another troop to join.

As I looked at the bigger part of the video,

the longer video clip, this was clearly almost all males together.

They could be brothers, they could be siblings of some kind.

These two animals would have known each other.

OK. But this is hardly the gentle care of brothers-in-arms.

The macaque's behaviour is brutal.

They are not fragile flowers.

I mean, I like to think the macaques are fairly bombproof.

If he had wanted to hurt that animal, if he had wanted to kill him,

there is nothing that would have stopped him.

It's clear that this animal is committed to getting this

other monkey back on his feet.

So, this truly is tough love?

One friend saving another?

But how on earth did he know what to do?

The wires that actually are extended throughout these

urban areas are a great...they are like highways for macaques, you know?

They are constantly moving across them.

A handy shortcut, but pick the wrong wire

and you're in for a shock.

Electrocutions are very, very common for monkeys in Southeast Asia.

Lisa believes that this macaque is no stranger to electrical mishap.

She thinks he's been in this situation before.

They've seen animals get electrocuted,

they've seen them drop, and they know that they've got to go in there

and kind of do this very vigorous agitation.

This streetwise macaque has learned from previous experience that

brute force and perseverance can bring a friend back from the brink.

His buddy came in there and did what an urban macaque's going to do.

They're going to...they're going to assess the situation...

they're going to step in, they've going to change their behaviour.

They're going to adapt to the situation and he brought his buddy back.

That's a good monkey.

What can I say? For once, a happy ending, and we love a happy ending.

Really bizarre and remarkable too.

And there must be something about Indian train stations,

because this isn't the first piece of monkey madness

to hit the headlines.

Macaques may be kind to each other, but to us, they can be trouble.

Yeah, in parts of India, their populations have exploded.

Particularly in cities,

where they are making a real nuisance of themselves.

The station at Lucknow in North India was a favourite

monkey hang-out until the local authorities brought in a man

with a unique skillset to tackle these troublemakers.

Acchan Miyan is Lucknow's official monkey man.

The monkeys at the station are too used to people to be scared away

by them...but a man-sized monkey...

that's a serious threat.

Monkeys respect hierarchy, they respect authority.

Those monkeys know that somebody's here who's going to

kind of lay down the law.

And it's not the face paint, it's Acchan's acting that really counts.

It's the way he moves, it's the way he makes eye contact.

He doesn't even have to have a stick in his hand.

He can just kind of walk through in a way that every

monkey's going to be like, "Oh...

"Maybe we should leave."

Well, the dressing up might not be entirely necessary,

but I suppose it demonstrates a certain sense of commitment.

But on the whole, what a fabulous idea.

A dominant male on the block means we don't have to take any more

drastic measures to get rid of those monkeys,

which is good...and clever, too.

Although I have to say, I probably can't take recent reports

of dressing up in Japan quite as seriously.

Tama Zoo, near Tokyo.

And that...

well, that's the head keeper dressed up as a snow leopard.

DISTANT MEGAPHONE CHATTER

Why? Well, the zoo staff are taking part in break-out tests...

..rehearsing procedures should any of their animals

escaped in the event of an earthquake.

Oh, look...

bang!

There goes the tranquiliser.

And he's down.

Method acting at its, er...best.

Now, this might look like some strange new Japanese game show,

but actually, this role-play is quite serious.

In June 2015,

a major flood set zoo animals loose

on the streets of Tbilisi, in Georgia.

Rescue workers managed to save some, but very sadly,

many animals were lost in the unfortunate aftermath of this event.

Keeping animals and public safe

is at the heart of this bizarre yearly escapade.

And, in fact, it's become so popular with visitors

that other wildlife parks around the world

have now been inspired to follow suit.

OK, I suppose it's a bit of fun and perhaps one day,

after all of those bizarre rehearsals,

if there's a real emergency at the zoo, it might all end well.

But at Israel's Ramat Gan Zoo,

keeping the residents ON the premises isn't the problem.

This is Dorit...

an Indian crested porcupine,

native to Israel.

Abandoned as a baby, she's been hand-reared by the staff at the zoo.

We got really, really attached to her.

We've known her since she was just a cute little tiny baby.

They raised her here at the wildlife hospital, so we all got to chip in

and bottle-feed her and get really, really attached to her,

and see her grow into this beautiful, beautiful porcupine.

And for nearly a decade, Dorit's lived a quiet life.

That was until early 2015,

when strange sightings started to concern her keepers.

Like, every morning, I came to the exhibit to see Dorit,

to feed her, to clean the yard.

And one special day, I came here and I saw the poop.

Instead of being inside the exhibit, it was outside.

And I thought to myself, "One of the keepers was very lazy yesterday.

"Instead of putting it into the garbage, just swept away.

"Never mind! I'll clean it up."

The other keepers denied any slacking,

but the poo kept appearing.

I came another day and I saw again the poop was outside of the exhibit.

Then a couple of weeks later, just as the mysterious poo

was starting to become a bit of an issue, an alarm went up.

A call from the primate department came,

"Your porcupine's out on the loose, we see her, she's right here.

"She's escaped."

We rushed to Dorit's enclosure and there she was,

just being her happy old Dorit self.

How could Dorit have been in two places at once?

It was time to get to the bottom of this mystery.

We decided to put a camera trap, because they're nocturnal,

they're mostly active at night and we wanted to see what was going on.

At first, just a few feral cats...

..a frisky cock...

But then...

We realised when we looked at the footage that there is a male

porcupine that comes in every night for the past month to visit her.

Dorit wasn't breaking out...

a wild male was breaking in!

He's not just defecating next to her,

he's actually interacting with her through the bars.

They touch noses, they sniff each other.

Dorit had a secret lover.

It's most likely that he smelled her and came all the way into the zoo

to meet her, which is quite exciting.

Porcupines, you see, give off a very powerful scent

that their quills help to stir up and distribute over long distances.

It's how male and female porcupines find each other

and then become inseparable for life.

Dorit's lover was so intoxicated with her aroma that he travelled

through the Safari Park, past the hippos, past the rhinos

and the giraffe, just to be by her side.

The story kind of broke our hearts

because he found a very special lady but he can't be with her.

We can't quite release her because we're afraid for her,

she's imprinted on people.

We're afraid that she'll come close to people

and that they'll hurt her.

We can't bring him in to her because he's a wild porcupine

and it's unfair to bring him into captivity

when he belongs out in the wild.

So the zoo staff are left with only one option...

to hope that frustration eventually gets the better

of Dorit's late-night lover.

So we're hoping for him that he'll give up one day

and find, you know, another wild porcupine to be with

and now that we know that Dorit is interested in boys,

we'll definitely consider bringing her a nice boy porcupine to be with.

I hope for her to find a nice man also handsome like her.

Alas, poor Dorit.

No, don't worry, it's not her.

Porcupines are one of my favourite animals,

I wouldn't do that sort of thing.

But perhaps, you know, this tragedy could end up with a happy ending.

It could end up as a sort of romantic comedy

for our spiny star-crossed lovers.

From a macaque with CPR skills...

to a monkey man in disguise...

..bizarre break-out drills and late-night break-ins...

we've lifted the lid on a weird world of strange secret behaviours.

Finally, from a man-mole to a congealed colony of deep-sea clones.

So let's head south...

Deep South.

Early morning, deep in the Apalachicola Forest, Florida.

METALLIC GRUMBLING

A strange sound breaks the quiet.

METALLIC GRUMBLING

Not made by a forest creature,

but by a man already very hard at work.

I not only love what I do...

..I'm bonded to it.

It's in my blood to do this.

I don't...

yearn for any other type of employment.

METALLIC GRUMBLING

It's safe to say that Gary doesn't do your average day job.

There's a technique to it, there's an art to it.

It's like playing an instrument.

Either you can play it or you can't.

Gary makes a unique noise that fellow Floridians in the know

call a grunt.

- It's a strange sound... - METALLIC GRUNTING

..but with an even stranger purpose.

You see, Gary is a hunter.

And his grunting brings in the most unexpected catch.

There's no other technique that I know that can get these

worms like this, with this right here,

this simple wooden stump and this piece of iron.

Earthworms are irresistibly drawn to Gary's grunt.

He then sells them as bait to fishermen.

And not just the odd one or two.

You know, I want to say maybe 3,000 to 4,000 to 5,000 a day

is a good day.

That's a lot of worms.

And there's certainly no arguing that worm grunting works.

The proof...

Well, look. It's everywhere.

But how does it work? Why are worms so drawn to this strange sound?

Word about Gary's unique skill set

reached the laboratory of an eminent scientist,

who was instantly hooked by the worm grunting mystery.

I'd heard about this technique where you pound a stake into the ground

and you cause these giant vibrations and this brings up

thousands of earthworms to the surface.

That's a real mystery,

because if you think about it, being on the surface

of the soil is the last place you want to be if you're an earthworm.

There's birds and snakes and lizards and ants and all kinds of things

that can eat you, not to mention you're out in the sun.

So it's the last place you would ever want to be.

Why on earth would an earthworm come up out of the ground

when it senses vibrations?

There has to be a good reason.

So Ken went to see the worm grunters in action.

We got married in 1970 and we've been worming ever since.

Things are usually not as good as the stories.

- This was - better - than the stories.

I mean, up came the earthworms out of the ground.

Audrey could go around and collect thousands of them.

It was just really something to see and they're huge earthworms,

so it's really dramatic.

Now, we all know that worms prefer to live below the surface.

And that there is one circumstance when they tend to pop up

and that is when it's raining.

So Ken had a theory which he thought could solve

this worm grunting mystery once and for all...

that Gary's vibrations were replicating

the pitter-patter of rain, right?

Well...actually...no.

Earthworms come to the surface after a long rain,

but it usually takes a whole day of rain or at least hours of rain.

You don't see earthworms fleeing to the surface at the first raindrops.

Ken had a hunch that something much more dramatic was causing

this behaviour and that hunch was that so many worms

would only surface so quickly if they were running scared.

If you're chasing your dinner, you don't want to risk your life.

But if you're about to be dinner,

you need to risk your life to escape.

And his suspicions were confirmed

with the help of an old friend.

Darwin says that it has often been reported,

when the ground is beaten or made to tremble, that worms believe

they're pursued by a mole and will exit their burrows to the surface.

Yes, Ken thought the vibration of Gary's grunting

was mimicking the tunnelling of the worms' ultimate predator.

He just had to prove it.

Gary had a bucket of worms,

and I had collected a mole, and we sort of looked at each other

and thought, "well, let's just do this."

Up came the worms, streaming out to the surface,

and that was just great because the two of us sort of together,

Gary and I, looking into this bucket,

sort of looked at each other and thought, "it's probably moles."

Without knowing it, worm grunters are perfect mole impersonators.

The sound that the worm grunters are making is like

the giant mother of all moles.

To an earthworm, that's a terrifying sound.

That's what he told me. He said, "You're a giant mole."

I said, "That works for me."

What a thing! Worm grunter and biologist

coming together to solve the weirdest-sounding mystery out there.

It doesn't get more perfect.

Grunting sends earthworms fleeing to the surface.

But, you know, there was another subterranean creature

found in North Carolina that the residents

clearly wished had remained underground.

The city of Raleigh.

Leafy,

quiet,

safe.

Well, until the spring of 2009

when all that changed.

We're a mid-size government town. A lot of beige architecture.

Don't get a lot of, uh, monsters.

Like every city, below the roads and pavements is a network of sewers.

And like in every city, they need inspecting.

We have to monitor the condition of the pipes on a frequent basis

because they can get blocked.

Strange things you'll see are snakes,

money, there's jewellery.

And we certainly see our fair share of rats.

But on April 27th, the cameras captured something,

the likes of which this city had never seen.

So, it appeared that they were going down either a six or eight inch pipe,

with this...with the robot, and they came across a...

..really unusual, somewhat animated...

..um, slimy...substance.

The feed from the cameras showed a bizarre clump

of a strange and unidentified substance.

Slimy and smooth,

reacting to the robot's light.

Pulsating and morphing.

I was at a loss for an explanation.

It was, um, really something

that I've seen out of a science fiction movie.

The discovery of something strange lurking in the sewers didn't

stay secret for long.

There was a clamour, you know. A great alarm in the streets.

It was as though Godzilla had shown up. We were all extremely excited

and, of course, dashed right out to find out about it.

The sewer blob became a sensation.

Everyone had their own theory.

SCREAMING

There was a movie called The Blob,

and so everyone was making a lot of Blob references.

There were...

People thought that it was pudding come to life.

People thought that it was radioactive.

We were getting a lot of questions

and, unfortunately, we didn't have any good answers.

Maybe it was an experiment gone wrong.

Maybe something slithered out of a test-tube and into the sewer system.

If only. But what was the truth behind the headline?

Fingers pointed towards these.

Bryozoa.

Thousands of tiny aquatic animals that live together,

clustered along the bottom of ships and docks.

But this theory didn't quite add up.

Most Bryozoans live in the ocean and actually have these hard little

coffin-like boxes that each Bryozoan body is in.

When there's a lot of them in one place, they can look like a big fleshy blob.

However, this blob was a bit too big

and not quite the right colour to be freshwater Bryozoans.

So, what was this pulsating mass?

Could there really be a sensible scientific explanation?

These are worms, annelid worms -

actually, close relatives of earthworms.

It's actually not quite known how many species,

but they're loosely called tubifex.

Tubifex worms live in the water,

anchoring themselves against the current

and grabbing food as it passes.

Tubifex, in the wild, typically lives in stagnant water.

They can handle quite low oxygen.

They have this deep red blood that gives them their colour.

It allows them to absorb the oxygen through their thin skin.

The prime real estate for something like a tubifex is somewhere

where you can attach to the bottom firmly, and there's food going by.

Obviously, a sewer wouldn't be our first choice for a home,

but for a tubifex, it's absolutely perfect.

That many resources in one place, you can get really dense clumps of them.

So, not a single monster at all, but a colony that moves like one.

Each worm can sense movement around it and it can also contract,

so that's almost like a chain of dominoes.

- This town is in danger. - 'How can it be stopped?'

I think people are generally weirded out by whatever

lives in the sewer, and if it's a giant, shiny, slimy,

pulsing ball of worms, then I can understand why they'd be grossed out.

There could be tubifex in a sewer right under your feet right now.

That might be a horrifying thought - unless, of course, you're Josh.

I think that the sewer monster would make an excellent mascot.

I don't know why anyone didn't print T-shirts.

OK, I know a ball of tubifex doesn't exactly constitute a monster,

but it is pretty revolting.

But then, I suppose, if you're a worm living down a sewer,

you don't really have to care too much about your looks.

But that's not to say that all colonial animals are horrid.

Some of them are exquisitely beautiful.

Deep below the surface,

a group of scientists are surveying the ocean floor...

when they spot something unusual.

What the...?

- Oh, it's... - Oh.

Garbage?

My goodness.

Their remote camera picks up a bizarre object

moving in the current.

- Oh, my gosh! - I can't believe that's a living thing.

That's amazing. Oh, how cool.

What?

Spotting this strange sea creature has made these

seasoned scientists a little bit giddy.

What is this?

I guess siphonophore?

Yup. Wow.

You've probably never heard of a siphonophore.

But Dr Dunn understands their excitement.

I remember the first time I saw a siphonophore

live in the water.

They look like swimming glass chandeliers.

They look like nothing else.

It's as if, all of a sudden, there's this whole new life form

that you've never heard of, right in front of you.

But what is this beautifully bizarre animal?

A siphonophore is a cnidarian, so it's a relative of corals

and many of the jellyfish that people are familiar with.

Siphonophores live in the open ocean,

forming the most intricate shapes in astonishing colours.

They look like glass sculptures. They're absolutely beautiful.

They really look like something from another world.

And what might really surprise you is that these

spectacular sea creatures aren't rare.

Siphonophores are the largest,

most abundant organisms that most people have never heard of.

Most people haven't seen a siphonophore,

because they're so fragile that they're destroyed before they get

close to the coast. They're just turned over in the waves.

They can't handle the sediment in the water.

Siphonophores are undeniably exquisitely beautiful creatures,

but that's not why Casey has given up so much time to study them.

No, it's because they are one of the weirdest animals

living in our ocean.

You see, the thing is, strictly speaking, they're not one animal.

When we're born, we have one cute little baby body,

and then that baby body has all the parts of the adult

but they just get bigger as we enlarge.

A siphonophore grows in a completely different way.

What they do is they're born as one little baby body,

and then instead of that baby body growing,

that baby body just makes more baby bodies.

Each of them are specialised for particular tasks.

Some bodies are specialised for tasks like feeding.

Others are specialised for tasks like swimming.

And this growth continues in a conveyor-like fashion

through the life of the siphonophore.

So, if we grew like a siphonophore,

we'd start life as a baby,

but rather than growing bigger,

this baby would grow more babies out of its side.

Some of these babies would only be able to eat

because they'd only have a mouth.

Other babies would only be able to walk because they just had legs.

But together, these connected babies could satisfy all the tasks

needed for a human to survive.

OK, so what's the biggest thing swimming in the ocean?

It's the blue whale, of course.

But you know the bizarre growth form of those siphonophores

means that the longest of them

can stretch out to more than 40 metres,

which is ten metres longer than the biggest blue whale.

So, worms are terrified of moles...

and Gary.

And if you want to scare the residents of Raleigh,

group together in sewers.

It was a little frightening.

But in the deep ocean, a colony can create a creature unique enough

to excite the most serious of scientific brains.

- Oh, gosh! - Awesome!

It's a weird, weird world.

And it's only going to get weirder.

Next time, what's caused this shadow in the sea?

Immediately, we thought it was an oil slick.

What else could it have been?

And why is this lemming so angry?

Why do dogs spin?

And can you really use your ears to see?

I am a man who uses the techniques of a bat to navigate.

How do you explain these bizarre circles?

And how do you get gold from poo?