All language subtitles for Natural Curiosities S01E07 - Defence and Deception CC HDTV x264 AC3 1080p

The natural world is
full of extraordinary animals

with amazing life histories.

Yet certain stories
are more intriguing than most.

The mysteries of
a butterfly's life cycle

or the strange biology
of the Emperor penguin.

Some of these creatures
were surrounded by myth

and misunderstandings
for a very long time

and some have only recently
revealed their secrets.

These are the animals that
stand out from the crowd.

The curiosities I find
most fascinating of all.

Some animals appear
to protect themselves

with formidable suits of armour.

The rhino carries plates
of thick hide on its flanks.

While the hedgehog is
covered in prickly spines.

Both, in previous centuries,

inspired far-fetched
and outlandish ideas,

but what is the true nature
of their strange coats?

Some animals have mastered
the art of deception.

The cuckoo tricks other birds
into raising its young,

while the death's-head hawkmoth
infiltrates the nests of bees

to steal their precious honey.

They're cheats and impostors.

Rhinoceroses are strange-looking
creatures.

There are five kinds.

The Indian, this one, has a single
horn, squat legs, tiny eyes...

Whoa!

..and thick folded skin.

For many centuries,
before any had reached Europe,

they were surrounded by myth
as much as the unicorn.

Few people had ever seen
a live rhino, but, in 1741,

a young Indian rhinoceros called
Clara came to Europe

and she transformed our image and
understanding of the rhinoceros.

Thank you.

Before Clara arrived,

Iittle was known in Europe
about the rhinoceros.

A few animals arrived here in Roman
times, but they didn't last long,

many being slaughtered during
the brutal Roman Games.

It wasn't until the 16th century

that they first made
a real mark on western society.

In 1515, a woodcut of a rhino was
created by an artist called Durer.

It was a beautiful image
of an elaborately armoured creature,

but it was inaccurate.

It's doubtful whether Durer
ever saw a live rhinoceros.

It's little wonder that
the rhinoceros was thought of

as a magical mythical creature

if Durer's woodcut of 1515
was to be believed.

He shows an armour-plated beast
with a large horn

and a strange little
spike on its back.

But in the 18th century,
the perception of the rhinoceros was

to change when Clara came to Europe
on an extraordinary 17-year tour.

Clara was captured in Assam
at just a few months of age

when hunters killed her mother.

A director of the
Dutch East India Company

raised her in his household
as a pet.

She wandered indoors amongst
the elegant furniture,

ate from a plate and was a popular
attraction at his dinner parties.

But, inevitably, Clara got too big

and a little-known Dutch sea captain
called Van der Meer

seized the chance to own possibly
the only tame rhino in the world.

He saw the opportunity of making
a lifetime's income

with an ambitious rhinoceros tour.

Clara became an orphan while she
was still dependent on her mother.

Rhino calves usually stay with
their mothers for up to two years,

sustained by the milk.

Only after that are they able
to feed independently

on soft green grass.

Keeping a young rhino healthy
was certainly a challenge,

but Van der Meer was smart and took
good care of his new charge.

He travelled with her
all the way from India

around the Cape of Good Hope, up the
coast of Africa to the Netherlands

and his home town of Leiden.

He discovered very soon
that Clara had a huge appetite

and he made sure that she always
had plenty to eat.

Rhinoceros spend
a great deal of time feeding.

They eat plant matter, but
they don't have multiple stomachs

to digest and absorb nutrients,

so they need to eat large quantities
of food to survive,

up to 100 kilos a day.

It takes a lot to fuel
such an enormous body.

An adult rhino weighs over a tonne.

And the Indian rhino
has a special mobile lip

to help it grasp
and rip up the vegetation.

After reaching Europe, Clara lived
quietly in Leiden for two years,

feeding and growing,

while Van der Meer made plans
for his European tour.

At the time, a live rhino
was a wondrous thing,

as Van der Meer well appreciated.

He was a clever businessman and
he knew that publicity was needed

if his grand tour
was to be a success.

Van der Meer made an unusual
alliance with an ambitious

Dutch anatomist, BS Albinus,

who was hoping to produce
a definitive medical textbook.

Both men were looking for publicity

and together they commissioned
Jan Wandelaar,

an accomplished artist,

to make prints that would serve to
advertise both the book and Clara.

They were strange but compelling
pictures that combined

precisely drawn human skeletons
and detailed images of Clara.

They were the most accurate drawings
yet of the rhinoceros.

Wandelaar sketched Clara from life.

He was fascinated
by the texture of her skin

and he depicted a rhino more
realistically than Durer did,

so, at last,

the myths surrounding the
animal's appearance came to an end.

As the news of Clara's tour spread,

everyone was eager to see
this wonderful new creature

and Clara's first trip to Vienna
was for a royal appointment.

The Empress Maria-Theresa
was so eager to see Clara

and so impressed by her appearance
and good temperament,

that she brought her children
back for another private showing.

Clara became the talk of the town

and European heads of state
were eager to meet her.

She travelled through Europe
like a celebrity

and met both royalty
and crowds of curious onlookers.

Her horn in particular attracted
much attention.

In Paris she started a rhino-mania

with fashionable women styling
their hair 'a-la rhinoceros!'

Some regarded rhinos
as living unicorns.

The scientific name for
the Indian rhino is, in fact,

Rhinoceros Unicornis,

and, at the time, it was believed
that the horn was made of bone.

But this in fact is not the case.

Rhinoceros horn grows from a spongy
base positioned here on the skull.

The horn has no bony core.

It's made of keratin,
the same substance as fingernails

and can grow again if it's lost.

Well, in June 1750,
Clara's horn fell off,

probably due to her rubbing it
on the travel crate.

To Van der Meer,
this seemed to be a disaster

since he had no idea
that it would regrow.

But, ingenuously, he used the event
as a publicity stunt and the crowds

flocked all the more to see Clara
fearing that she might be dying.

Even without a horn, Clara was
still a fascinating creature

and her strange armoured skin
was another talking point.

Why would such a gentle creature
have such thick and elaborate folds?

The rhinoceros's skin in some parts
is almost five centimetres thick,

nearly three times thicker
than you would expect

for an animal that size.

We now know that, in the wild,

rhinoceros are not
always as gentle as Clara.

They can be very aggressive,

particularly during
the mating season,

and the tough skin
provides them with some protection.

But it also has other benefits.

Thick skin is a good barrier against
sun, flies and other parasites,

but why the skin of an Indian rhino
grows in plate-like structures

with deep grooves has only
recently been explained.

We know that the thicker skin areas
are good physical protection,

but something deeper is going on.

It seems that the large folds
increase the surface area

of the skin and help the rhino
regulate its body temperature.

The tissues around the grooves are
particularly rich in blood vessels

and transmit heat to the
enlarged skin plates

which act like cooling radiators.

Indian rhinoceros bathe regularly
and the folds in their skin

not only trap water but hold it
even after they come back onto land.

So it turns out that
the Indian rhinoceros's skin

is a far more specialised structure
than anyone could have imagined.

For 17 years,
Clara travelled across Europe,

stopping off in all
the main towns and cities.

Everywhere she went,
the crowds queued up to see her.

She visited England three times,

but her third visit
proved to be her last.

In 1758,
at the age of little more than 20,

Clara unexpectedly died in London.

Van der Meer was deeply shocked as
he thought she might live to be 100.

Life on the road was over,
but Clara's 17-year tour

had changed the image
of the rhinoceros forever.

Durer's classic engraving
of the fierce armoured beast was now

a part of history and new accurate
images were produced.

The true Indian rhinoceros,
like Clara,

Iooked just like this
wonderful animal

painted by the great 18th-century
artist George Stubbs.

Van der Meer made his fortune
with her on the grand tour,

but Clara, more importantly,
also enabled people

to get a first realistic view
of what a rhinoceros looks like

and put to rest the idea of a
heavily armoured mythical creature.

There is a more familiar animal
whose body armour

also perplexed us
for a surprisingly long time.

The hedgehog.

This delightful little creature
is one of our most familiar

garden animals and yet it's got
a surprisingly unusual appearance.

Instead of fur, like most mammals,
it's got a thick coat of spines.

The only part of its body
not covered by them

are its face and its underside.

The hedgehog's coat may appear
to be painfully prickly,

but when the hedgehog is relaxed,
it can lay its spines down flat.

When it senses danger, of course,
it rolls itself up into a ball

and is completely hidden
and protected.

It's a formidable suit of armour,
these spines.

Nothing much can get past them.

It seems obvious that spines
must serve as a protection

but their function was, in fact,
misunderstood for a long time.

Early books claimed the spines
were used for collecting food.

The hedgehogs were said to
climb apple trees,

knock down the fruit and roll on it,
impaling the apples on their spines

and carrying them off
to their burrows.

Today we know that hedgehogs
are better at climbing

than you might think, but they still
haven't been seen to climb trees.

And there were other myths.

In medieval times, farmers believed
that hedgehogs would steal milk

from their cows at night.

So the Elizabethan Parliament put
a three-pence bounty on the head

of every hedgehog and thousands
were slaughtered as a result.

Our attitude to the hedgehog
is now very different.

Today, many of us get great pleasure

from seeing this appealing
little creature in our gardens.

We know that they are
a gardener's friend,

feeding mostly on insects and slugs

and helping to rid
our plants of pests.

Some of us even put out special
food to attract them.

We now also understand
more about the hedgehog's spines.

They are, in fact, modified hairs,

hollow inside
but reinforced with keratin,

the same material that
forms a rhinoceros's horn.

That makes them strong while keeping
weight down to a minimum.

A hedgehog has over 5,000 spines

and their main purpose
is indeed protection.

But hedgehogs don't start life
with a coat of armour.

It would be painful
for a hedgehog mother

to give birth
to spiny babies.

But nature has dealt
with that problem.

Tiny hoglets are born with their
spines covered by a layer of skin.

Within a few hours,
the thin quills break through.

A baby hedgehog's first
spines are soft and white

but these soon fall out and are
replaced by darker and harder ones.

Hedgehog spines are shed and regrown
at various stages in their lives,

just like the hair of mammals.

Surprisingly, a spiny armour is not
common in the animal kingdom.

In Europe, the hedgehog
is the only one of its kind.

But in other parts of the world,
there are creatures that have

evolved a similar spiky coat.

This is an African crested
porcupine.

It's got a formidable coat of spines
but it's no relative

of the hedgehog and the
spines are in fact very different.

For one thing,
they are very much longer.

Normally, they lie flat against the
body but if the animal is irritated,

it directs them
to give a very spectacular warning.

Even the most ferocious predator
will take care

when approaching a porcupine.

The quills will break off easily
and become lodged in the skin.

The lion's only chance
is to attack from the front.

As they circle,
the porcupine twists and turns

to keep its armoured back to them.

This time, the lion got too close.

It has no way of removing the
spike and may be unable to feed.

It could prove fatal
for the predator.

Although the porcupine's quills
may appear thin, even flimsy,

once they get stuck in your flesh,
they are remarkably difficult

and painful to remove.

Why this should be
was not known until recently.

But when looked at under
an electron microscope, you can see

that each quill is coated with
tiny backwards facing barbs.

The barbs act like
the teeth on a serrated knife,

making it easier
to penetrate the skin,

but when it comes to
removing the quills,

the barbs have the opposite effect
and act as anchors,

preventing the spine
from sliding out of the wound.

The porcupine's spiky coat seems
more formidable than the hedgehog's.

But the hedgehog has a very
effective way of protecting

its vulnerable underbelly.

It rolls itself into a ball, so that
it is completely encased in spines.

Foxes do attack hedgehogs
but a fox must wait until the animal

is on the move if it is to
get at its unprotected underside.

If the hedgehog stays
rolled in a defensive ball,

the fox can't harm it.

All the hedgehog has to do is to sit
it out until the fox loses interest.

But if spines are such
an effective defence,

why don't many other
animals adopt them?

The answer seems to be connected
with the difficulties

of life with spines.

Spines may be something of a
hindrance when it comes to mating.

Indeed, early naturalists
thought that the hedgehogs must mate

belly to belly to avoid being
impaled on each other's spines.

We now know that
that's not the case.

The spines seem to do nothing

to hinder the ardour
of a male hedgehog.

If she is willing,
he tries to oblige.

But it still looks like a tricky
and uncomfortable operation.

Despite the limitations
of a spiny coat,

hedgehogs have remained
largely unchanged

for almost 15 million years.

New evidence suggests that
the spines may play another

rather surprising
role in their lives.

Hedgehogs, when encountering
an unfamiliar or toxic object,

sometimes behave
in a very strange way.

They will lick and bite it until
they start to foam at the mouth.

The froth is then transferred
to their spines.

We still don't fully understand
this strange behaviour.

It may help to camouflage
the hedgehog's smell,

or make the spiny coat
more distasteful to predators.

Or maybe it helps hedgehogs
communicate with each other.

Or make them more attractive
to the opposite sex.

We might one day discover its
true purpose but we haven't yet.

Our familiar British hedgehog
has provoked some very strange

and far-fetched ideas,
but, for many of us,

it remains one of the most engaging
animals in the British countryside,

and its prickly coat makes it
that much more attractive.

So, it turns out that some of
the early ideas about the purpose

of the rhino's armour
and the hedgehog's spines

were only partly correct.

Their true functions are far more
complex than we yet realise.

CUCKOO CALLS

The call of the cuckoo has long been
regarded as a sign of spring.

But, in fact, it's the call
of a killer and a cheat.

The cuckoo lays its egg in the
nests of other birds and somehow

persuades them to treat it and its
chick as if it were their own.

How does it get away with it?

It's a question that has puzzled
people for centuries.

In Britain,
the cuckoo arrives at a time

when most birds are nesting
and laying eggs.

Early egg collectors
noticed that the nests of some birds

had a slightly
odd-looking egg in them.

These are the eggs
laid by a number of different birds.

A marsh warbler, spotted flycatcher,
a linnet and a whitethroat.

Amongst each of those clutches,
there is a fraudster, a cuckoo egg,

which mimics that of its host.

Although cuckoos are long known
to lay their eggs in the nests

of other birds, no-one had
actually described it happening.

Then, in the 18th century,
an English country doctor

with an interest in natural history
decided to investigate.

Edward Jenner lived here
in Berkeley, Gloucestershire,

and is best known for his work
on the smallpox vaccine.

In fact, he is said to be
the father of vaccination and that

his work has saved more human lives
than that of any other man.

What is less known is that he first
achieved scientific distinction

by his observations
on the behaviour of the cuckoo.

At the time, it was believed
that a cuckoo removes

all of the eggs in a nest
and then lays its own.

By doing so, it would ensure
its own chick gets all the food

brought in by the
unwitting nest owners.

But Edward Jenner's detailed
observations were to reveal

a rather darker tale.

Jenner's work on cuckoos
was published in 1788

here in the Philosophical
Transactions of the Royal Society,

the world's first
scientific society.

It was entitled simply...

"Observations on the natural history
of the cuckoo"

by Mr Edward Jenner.

In it, he reported that it was not
the parent cuckoo

but the newly hatched chick
which pushes the eggs

and nestlings of the foster parents
out of the nest.

As soon as it hatches,

the cuckoo chick's instinct is
to kill anything else in the nest.

It's still blind and naked

but it has a cup-shaped depression
on its back

into which an egg fits perfectly.

But sometimes the other eggs hatch
earlier and Jenner's observations

of how the cuckoo chick
deals with its nest mates

were quite shocking.

He writes...

"the moment of accomplishing
this was very curious.

"The little animal, with the
assistance of its rump and wings,

"contrived to get
the bird on its back

"and, making a lodgement of the
burden by elevating its elbows,

"clambered backwards with
it up the side of the nest

"until it reached the top,
where, resting for a moment,

"it threw off its load with a jerk

"and quite disengaged it
from the nest."

The real villain had been uncovered.

Jenner's views were met with
incredulity and some disbelief,

but nonetheless they earned him
the Fellowship of the Royal Society.

It was the greatest honour
that could be given to

a scientist at the time.

Jenner's observations had revealed

the true nature
of the cuckoo's deception.

But it still wasn't clear why
the cuckoos should opt for this

strange way of raising its young.

It wasn't until 100 years later
that Charles Darwin finally

provided an explanation
with his theory of evolution.

The cuckoo's behaviour has evolved

to increase its own
breeding success.

By avoiding the task
of raising chicks,

the cuckoo can lay
more eggs than any other bird,

as many as 25 in a season.

While it makes evolutionary
sense for the cuckoo

to lay its eggs in the nests
of others, what about its victims?

Why do they put up
with this trickery?

It seems that they sometimes don't.

This was revealed in an early
natural history film in 1920.

The Cuckoo's Secret was made
by Edgar Chance and Oliver Pike,

an egg collector
and a wildlife film maker.

Chance was fascinated by cuckoos

and spent a great deal of time
following them.

He was the first person known
to see a cuckoo lay its egg.

The deception involves
stealth and speed.

The female waits until a nest is
unattended and then she strikes.

But if she is spotted,
the owners fight back.

If she is successful,

the whole deception
takes less than ten seconds.

She removes and eats just one egg
and replaces it with her own.

The Chance and Pike film
solved one mystery,

but there were still others.

How does the cuckoo
choose its victim?

And why don't the nest owners
reject the alien egg?

Reed warblers are one
of the cuckoo's main targets

and the pair has a nest
just in here.

The female warbler
has laid four speckled eggs,

and, using a model egg, I can
illustrate the cuckoo's trickery.

This is the sort of egg
that a cuckoo would lay

in the reed warbler's nest.

It matches the reed warbler's
actual egg very closely in colour.

Experiments with model eggs
have shown that reed warblers

have become very good
at recognising an alien egg

and either throw it out or
desert their nest to start afresh.

So the cuckoo has to make
sure that it produces an egg

that is a very good match.

The cuckoo and its victims
are evolving competitively.

With each generation,
cuckoos improve their mimicry,

while the nest owners become
better at spotting a foreign egg.

While many birds are very good

at detecting a strange egg
in their nest,

they seem incapable of recognising

the monstrous cuckoo chick
as an impostor.

But the deception is not complete.

The young cuckoo is much larger
than the reed warbler chick

so it also needs a lot more food.

How does it get enough?

The cuckoo has a solution.

It now uses vocal deception
to trick its foster parents

into providing more food.

This is a sonogram of the sound
waves produced by a single

reed warbler chick begging for food.

Below it is the call
of a cuckoo chick,

and, as you can see,
it looks very different.

In fact, it more closely resembles

the calls of a whole nestful
of reed warbler chicks.

So, the cuckoo chick's call
is a super stimulus

that sounds like a whole
nestful of chicks.

And it appears to work.

The adult birds rush back and forth,

providing the impostor with
the same amount of food

as they would for an entire
brood of their own.

At three weeks old, the cuckoo chick

has spilled out of the nest.

It's now almost eight times
the size of its foster parent.

It was over 200 years ago

that Edward Jenner first shocked us

with his revelation of the cuckoo's
extraordinary lifestyle.

Now we know
that its unusual behaviour

is due to an extraordinary
arms race

that has resulted in one of
the most fascinating

specialisations in nature.

The cuckoo's success relies on
deceiving just two parent birds.

But our second subject is a moth

that is able to deceive
hundreds of bees.

How does it infiltrate

one of the most heavily guarded
nests in nature?

This wonderful creature was once

one of the most feared
insects in Europe.

It's a death's-head hawkmoth,

and it's easy enough to see
how it got its name.

It has this mark on its back

that looks just like a human skull.

This gave it a bad reputation
that lasted for centuries,

but now there are new ideas about
this moth's strange appearance

that may help explain
its extraordinary ability

to rob hives without being stung.

Death's-head hawkmoths
are a rare sight Britain,

for they spend most of their lives
in Africa and Asia.

But every summer
a small number of migrants

arrive in northern Europe,

and, if the weather is warm enough,
they breed.

Their caterpillars,
unlike the drab adult moths,

are beautifully coloured.

After feeding for several weeks

they can grow to a length
of 13 centimetres.

Once ready to become adults,
they pupate in the soil

and emerge as the sinister,
strangely patterned moths.

In the early 19th century,

a region of northern France was hit
by a terrible pestilence,

and, at the same time,
a large number of hawkmoths

were seen in the area.

The local people linked the deaths
to these night-flying insects.

But there was another even more
disturbing side to this moth.

It could make an unusual noise.

SQUEAKING

There.

A strange squeak.

And that only added to
its chilling reputation.

Moths don't usually squeak.

Tiger moths sometimes produce
ultrasonic warning clicks

that tell bats that they're
poisonous and not good to eat,

but this is not a noise
we can generally hear.

Perhaps the death's-head
hawkmoth squeaks

to scare predators like birds.

However, other large migratory moths

don't make such a sound.

This makes the death's-head
hawkmoth's squeak

all the more surprising,

and it has intrigued
people for centuries.

These moths are more
than 200 years old.

We know that because
the handwritten label there tells us

they were collected in 1801
by a Robert Darling Willis,

the personal physician
to King George I I I.

George I I I is well-known
as the king

who suffered from bouts of madness,

and, on a visit to see
the king during one of them,

Dr Willis discovered these large
moths in the monarch's bedchamber.

Unable to identify them, the doctor
sent them to his grandson,

who was at that time superintendent

at the Museum of Zoology
in Cambridge.

He confirmed that they were
death's-head hawkmoths,

and, unusually for an insect,

this moth produces a loud call

that has been likened
to the mournful cry

of a grief-stricken child.

Did the disturbed king hear
the plaintive calls of a hawkmoth?

That we don't know.

But certainly many of the ordinary
people of the 19th century

were struck with a sense of terror
whenever this moth appeared.

The moths' unusual appearance and
strange behaviour baffled people.

But, in nature, such traits
usually have a purpose.

And it may be for
the death's-head hawkmoth

that they enable it to break into
beehives and steal their honey.

These are the giant honey bees
of south-east Asia,

and they form some of the largest
bee colonies in the world.

I once got up close to one
in order to demonstrate

their response to a predator.

I had a model of a large hornet,

which produced a
kind of Mexican wave,

and that makes it very difficult
for an aggressor to land.

BUZZI NG

This covering of bees looks
impossible to penetrate.

But at night

a thief can break through
their ranks.

A death's-head hawkmoth
lands on the carpet of bees

and pushes its way through
without being attacked.

In just a few seconds,
it takes some sips of honey

and emerges unharmed.

Getting past the guard bees
is quite a feat,

but surviving inside
is even more astounding.

Death's-head hawkmoths raid
domestic beehives too,

and can be quite a pest.

Somehow, the moth slips past
the guards and, as if invisible,

walks through the hive,
heading straight for the honeycomb.

It then feeds unnoticed.

How does it do this?

One theory proposes that
its spooky appearance

may help it avoid being attacked.

BUZZI NG

Miriam Rothschild,
a great entomologist

and expert on fleas
and butterflies,

suggested that the moth's
skull pattern looks like

the head of a worker bee,

and that this could play a role
in the moth's deception.

Well, this is a photograph

of a worker bee face taken
through a microscope.

Let's see how it looks
next to a close-up photo

of the skull pattern of the moth.

There.

Well, I suppose there's
a slight resemblance,

but given the fact that most moths
raid beehives and nests

during the night,
it's unlikely the bees

could see that much detail.

The most likely answer lies in
the scent the moth gives off.

In America in the 1950s,

a German entomologist called
Thomas Eisner

studied chemical ecology -
in particular,

the chemical defences of insects.

Most famously, he illustrated
how bombardier beetles

fire hot acid onto a predator.

He also studied moths,

and showed that the feathery
projections on their abdomens

and their large antennae were used
to produce and pick up scent.

It seemed that many insects were
using scent in surprising ways.

Tests on the chemical scents
produced by hawkmoths

reveal a remarkable similarity to
those produced by the worker bees

in the hives that they raid.

Their scent is not identical,

but it contains several
key chemicals

that exactly match
those produced by bees.

So the death's-head hawkmoth's scent

acts as an invisibility cloak

that makes it undetectable
to the worker bees in the nest.

With thick scales on its body,

clawed feet that grip the honeycomb,

and a short, pointed proboscis
to pierce the honey cells,

the moth has evolved into
an effective hive robber.

But there is another,
even more impressive impostor

that can also penetrate
the protective defences

of an insect colony.

Its victims are not bees but ants.

The impostor that invades
this ant nest

doesn't get in there by flying.

Nothing as blatant as that.

Instead, the caterpillars of some
species of blue butterfly,

Iike this one, wait for
red ants to collect them.

Remarkably, passing ants
don't kill them.

They pick them up and take them
back into their nest.

The cuckoo caterpillar will stay
inside the nest

for up to ten months.

Just like the death's-head
hawkmoths,

it produces a chemical scent
that deceives the ants.

This pink caterpillar, which
belongs to the alcon blue butterfly,

has been collected because,
to them,

it smells just like the young
of their own nest.

They become controlled by
the impostor's intoxicating scent,

and feed the butterfly larva
even more regularly

than they do their own.

There's another way this impostor
pulls off its deceptive trick.

When it's inside the nest,

the butterfly larva makes
a strange chattering noise.

To our ears, it's very faint,

but it's clear enough
to other insects. This is it.

CHATTERING NOISE

And this is the sound
that's made by a queen ant.

SIMILAR CHATTERING NOISE

To worker ants,
these calls are very similar,

and they react by treating
the butterfly larva

as if it's one of their own.

Caterpillars of the blue butterfly
are impressive impostors.

Not only do they mimic
the scent of the ants,

but their queen's calls too.

This seems to trump
the death's-head hawkmoth's ability

as a nest invader.

But the hawkmoth may also be using
sound to trick its victims.

Remember the eerie squeak that was
thought to be so frightening?

SQUEAKING

There.

The hawkmoth makes this sound
inside the beehive

when it enters to steal honey.

It's been suggested that
this might calm the bees,

because the squeak is thought
to sound like the piping call

that the queen honey bee makes
to pacify her workers.

We can't be sure if the call
and the strange skull marking

evolved to deceive bees,
but we can be certain

that the death's-head hawkmoth's
life as an impostor

is more curious than
the superstitions

that have surrounded it
for hundreds of years.

The cuckoo and the hawkmoth
are both audacious impostors,

but the cuckoo's ability to make
its victim raise its young

is perhaps the most accomplished
deception of all.