All language subtitles for Attenborough & The Empire Of The Ants

The Jura Mountains

on the French-Swiss border

are in the grip of winter.

The ground has been
frozen solid for months.

This is a tough place
in which to live.

I'm told that clearings like these
could be the home of a real giant.

At this time of the year,
it'll be in hiding.

But evidence of its existence -
these strange mounds -

is everywhere.

Inside here, deep down and protected

from the cold, the giant is asleep.

Beneath the thatch of spruce needles

lies a maze of tunnels and chambers -

the home of hibernating wood ants.

Individually, they are tiny,

but they're members of a giant
super-colony.

When temperatures rise, over half a
billion of them will emerge

and dominate this landscape.

Scientists are only just working out
how ants manage to survive up here.

But in fact there's a much greater
and more profound mystery

that has brought me up this mountain.

Among ants, cooperation between
colonies is very rare.

Warfare is common.

Yet these nests over a great area
live at peace with one another.

This may sound like an epic tale of
war and peace

but does it also contain
an echo of human nature?

These ants,
in some extraordinary way,

have exchanged war for peace.

It's now recognised

as one of the largest of all insect
super-societies,

and its very existence conflicts with
some of the laws of evolution

as we presently understand them.

It's been a long, cold winter here
in the Swiss Jura Mountains.

It's hard to believe

that any insect could survive
in this frozen landscape.

But now change is in the air.

Soon, ant nests all over this
mountain will come to life.

Some of these mounds
are independent colonies

but others are part of one huge
super-colony.

Over the coming months, I'll be
looking at the differences

between these two
wood ant societies -

one that wages war
with all its neighbours,

and the other, which welcomes them
and lives at peace.

As the grip of winter eases,

sentries emerge from the mounds
to check on conditions.

They detect the sign that they've
been waiting for -

the temperatures are rising.

Spring is on the way.

The ants survive the winter thanks to
their own central-heating system,

warmth given off by the slow
decomposition of the dead vegetation

in the nest's fabric,

and that prevented them all
from freezing.

Now, by swarming all over
the surface of the nest,

they are recharging their batteries,

absorbing heat directly
from the sun's rays.

This behaviour only happens over one
or two days in the early spring.

The worker ants have emerged
into the sunshine

and are now clumping together.

And they're not just sunbathing.

It could well be that
the ultraviolet rays of the sun

cure them of any infections
from viruses or fungi

that may have happened during their
long sleep underground.

You can almost feel the enthusiasm

with which these little creatures
are enjoying their sunbathe.

This is unusual enough, but now here
is something truly extraordinary.

There is a queen.

She's almost twice the size of her
subjects.

She's also the most important member
of her family.

And what's more, there's another.

To see a queen exposed and vulnerable
outside the nest

is very rare indeed.

There's one.

And there's another...

..shining wonderfully
in the sunshine.

A normal wood ant nest usually has
just a single queen

who lays all the eggs -
but clearly this is not so here.

There's another. There's another.
Several of them.

Amazing.

After a few moments in the sunshine -

the only time they see daylight
in the whole year -

the queens disappear

and make their way back to the
brood chambers deep in the nest.

Those unwilling to go
are dragged back.

We may call them queens,
but there's no sovereign rule here.

The workers govern by consensus,

and they decide when and where
the queens will go.

There may be hundreds of queens
in this single nest,

and there are over a thousand such
mounds as this, all interconnected.

So, across the super-colony

there may be as many
as a million queens.

It's now early April.

The queens returned below
to prepare for the egg-laying

started a race against the clock.

They must complete their most
important work below

in the next two months.

Using infra-red light,
which is invisible to the ants,

we can watch them inside their nest
without disturbing them.

Most of the first eggs to be laid

will produce the next generation of
breeding individuals -

the queens and the males -

both of whom will have wings.

Inside the thousand nests
of the super-colony,

over half a billion
mostly unrelated worker ants

cooperate to ensure that the
queens and the males will be ready

for their mating flights in mid-June.

With all these developments
on the way, it's imperative

that the workers collect more food
as soon as possible.

But many of the mounds are still
surrounded by snow...

..so the workers can't reach
their feeding grounds.

But there's something
they can collect -

heat.

The nest needs more heat

than that which comes from
the rotting vegetation

if the eggs are to hatch in time
for their June appointment.

Now, however, the ants have
another source of warmth.

Using their bodies as solar panels,

the ants harvest the sunlight.

We have a heat-sensitive camera that
detects differences in temperature.

The nest appears black

because it's hotter than the
surrounding environment.

It shows a similar difference
in the ants.

Those going down into the nest
are black

because they've been heated
by the sun,

whereas those coming out are white
because they're cold,

having transferred their body heat
to their charges

in the brood chambers below.

It's this kind of
selfless collaboration

that is the key to success
of any ant colony.

In normal ant colonies,

all the workers are related
to one another and to the queen,

and the theory is that that is why
they all cooperate.

But that is not the case here.

There are hundreds of queens here.

Over a thousand have been counted
in a single nest,

so all the workers can't have
the same parents -

and genetics have confirmed
that this is so.

It's this cooperation between
unrelated ants in a single colony

that appears to be rewriting
the rules of insect evolution,

but we still don't really know
how this has come about.

Spring is now well on the way.

The snow has disappeared,

and colour comes to the meadows.

By late April, there are piles of
eggs in the nest

and the first larvae are hatching.

The workers labour unceasingly
to ensure that the growing brood

will be ready to emerge
in six weeks' time,

at the peak of the short Jura summer.

But not every ant nest on this
mountain can be so focused.

Some will soon have to deal with
threats to their very survival.

Just a short distance away,

on the borders of the super-colony's
woodland territory,

there are other wood ants.

The mounds here on this side of the
mountain look exactly the same

as those of the super-colony,

and so do the ants themselves.

The inhabitants of each nest here
are all the offspring

of its single queen,

and the colonies compete aggressively
with one another.

After the winter hibernation,

the territories between that nest
over there and this one here

have become blurred, and the frontier
has to be re-established.

And in order to do that,

workers from both nests
are now scouring the ground,

and that brings neighbouring ants

into contact for the first time
this season.

When foragers from the different
nests meet,

they immediately recognise that
they're from rival families.

They then dash back to their nests
and within minutes both colonies

know that territory on their frontier
is being disputed.

Armies assemble.

This...is war.

And the weapons being used
are chemical.

Formic acid.

I can smell it in the air.

They're squirting it from the ends of
their abdomen,

and if they can bite their opponents

so that the formic acid gets beneath
the outer shell of an ant,

it will dissolve its internal organs.

As they grapple, each tries to
restrain its opponent

by clamping its jaws around a leg
or an antenna.

Soldiers from both sides
tug at their opponents' limbs.

It can take seven ants
to subdue a single enemy.

One holds each leg,

and the seventh uses its mandibles

to cut open sections of their
opponent's exoskeleton,

exposing the insides.

An attacker brings forward its
abdomen under its body

and squirts acid onto its victim.

Battles are going on everywhere.

Each colony carries its own chemical
badge, invisible to our eyes,

but clear to the ants'
sensitive antennae.

Fighters touch each other to confirm
whose side they're on.

Here and there, individuals clamber
up the vegetation.

Are they having a rest,

or are they surveying progress
to see where help is needed?

The smell of formic acid
reaches the colony,

and more ants from both sides
run to join the battle.

These wars can continue
for over a week.

At their peak, many thousands are
fighting and thousands are killed.

The victors will certainly have
enlarged their territory...

..but some say they have also gained
other rewards.

They're taking off the bodies of
their victims

and carrying them back to the nest
over there to feast upon them.

Both sides have suffered
heavy losses.

For the ants in the meadow, it has
been a costly start to the year.

Higher up the mountain, in the
territory of the super-colony,

the inhabitants of different nests
are also meeting.

But here, things are very different.

These ants come from a mound
about half a mile away.

If that mound was a separate,
independent colony,

then these, when they land there,

would be savagely attacked.

But let's see what happens.

At first, the resident ant
makes an aggressive gesture.

But then the other strokes
the first's antennae.

That gesture is a request for food,
and the other obligingly feeds her.

This behaviour -
known as trophallaxis -

is in itself not unusual.

Most ants do it at times.

What is unique is that these ants
are almost certainly unrelated,

yet they treat each other as if they
were from the same nest.

They do this because they share
the super-colony scent,

a chemical signature that is
transferred together with the food.

In one experiment, scientists fed
a distinctive chemical to a nest

on one side of the super-colony,

and eight weeks later that same
chemical appeared

far away on the other side.

It's this sharing of food between
over half a billion individuals

that makes this super-society
so truly remarkable.

Because of this, super-colony ants
can move freely between mounds,

and they have, as a result,

created over 100km of trails

that link over a thousand nests.

These trails not only allow the ants
to make new nests

deep in the forest,

they also give all the members
of the super-colony

access to resources
of great value to them.

It comes from the spruce trees.

The ants don't feed directly
on the spruce trees.

They've become farmers.

And these...are their flocks.

Aphids.

The presence of the ants
keeps insect predators at bay

so the aphids can feed unmolested.

They drink the tree's sap

and excrete what they don't need as a
sugary liquid called honeydew.

And the ants love it.

Just as human farmers
milk their cows,

so the ants stroke the aphids
with their antennae

to persuade them to release
their honeydew.

Once the aphids are milked

and the ants have drunk as much
honeydew as they can carry,

they head down the tree, abdomens
bulging, and return to the nest.

The honeydew is not only food
with which to sustain themselves.

Some use it to raise the heat of
their bodies well above normal,

and so warm the atmosphere
within the nest -

a valuable ability in the fickle
climate of the Jura.

The spruce trees themselves
also produce a substance

that the ants can use directly.

These ants have collected

little flakes of resin.

That's a sort of gum that oozes

from the broken twig

of a coniferous tree.

The tree uses it to seal off
an injury.

But what are the ants using it for?

Inside the nest, the extra warmth
produced by honeydew

helps the queens to keep laying

and the larvae to keep growing.

However, constant warmth
can create problems.

Despite regular cleaning,
diseases can thrive.

The ants have a remarkable solution
to that problem.

They cover the surface of the mounds
with tiny nuggets of resin,

and also take it
into the chambers below.

One nest contained
over four kilos of it.

It is, in fact, ant medicine.

The ants combine acid from their
bodies with the resin

and so produce a very effective
antibiotic.

This is one of the most sophisticated
animal pharmacologies

known to science.

It's been shown that wood ants living
in nests that contain resin

are better able to survive diseases
than those that don't,

and their eggs are far less likely
to be infected by fungi.

This immense, peaceful super-colony
has few enemies.

But now, at the end of May,
a new threat has arrived.

(BELL JANGLES)

(COW MOOS)

The Jura is famous for producing
some of Europe's finest cheese.

For generations, farmers have made
small clearings in the woods

to create meadows
where cattle can graze.

Only now is it warm enough

for cows to be brought up to these
high pastures.

Somehow, the ants need to make sure
that they're left alone,

and that nothing damages their nests.

And that's a considerable challenge,
even for a super-colony.

But these ants are very determined.

When one squirts its acid,
others follow suit.

The result is a coordinated barrage.

The cows are not harmed, but they do
get a dose of acid in the nose -

which they don't like -

and they tend thereafter
to avoid these mounds.

(BELL JANGLES)

By now, in June, the larvae
have become big and greedy.

They must be given special care

because they will produce
the next generation of royalty,

so the workers labour hard
to meet their demands.

In summer, hundreds of thousands of
eggs are hatching every day,

and honeydew is not enough.

The ants go in search of
something else. A supplement.

Fresh meat.

The lush green hills and mountains
of the Jura

are now teeming with
all sorts of life,

and nearly all of it
is potential food.

The ants spread out from the nest,

scouring every square inch of
the ground in search of prey.

As the hunters approach,
those that can, take flight.

The ants' vision is not very acute.

They can only see a target
if it moves.

A wolf spider, however,
can see the ants clearly.

But as long as she doesn't move,
they won't know that she's here.

She's carrying a little sac
full of eggs.

She decides to run for it, and her
sudden movement alerts the hunters.

That first fleeting touch by an ant
left a faint scent mark,

and now fellow hunters can home in
on their target.

The spider has a venomous bite,
but that is no use now.

Eight powerful legs
are her only hope,

but her speed is the very thing that
enables the ants to follow her.

Slow motion reveals the basic
ant-hunting technique -

lunge with jaws open
and hope for the best.

At last, an ant manages to grab her.

Like a pride of lions taking down
a buffalo, the ants surround her.

Two restrain their catch,

while another delivers
the flesh-dissolving acid.

The wolf spider is just one
of many victims.

Alone, an ant can take
only the smallest prey.

But by working as a team,

they can capture creatures
many times their size.

A super-colony can make hundreds of
millions of kills every year.

Beetles, caterpillars, worms, flies -

they will tackle
almost any living thing.

Whatever the prey, it's first cut up
and eaten by the workers,

who then regurgitate it
to feed to the larvae.

Once they have grown to full size,

the larvae spin silk cocoons
for themselves.

Inside each, a featureless larva
is changing into an adult.

Their time in the sun is approaching.

Wood ants live in one of the most
highly organised

and complex of insect societies.

They fight wars over territory,

they hunt in packs,
and farm other species.

They build complex homes
with central heating,

they produce their own medicine,

and one group of them, we now know,
has made another advance.

The super-colony has extended this
collaboration beyond the frontiers

of the family to form a super-society
of such dimensions

that we can perhaps begin
to compare it with that other

great social creature on this planet
- ourselves.

People studying the origins of human
culture suggest that shared myths

were one of the factors that bound
early human societies together.

But what about ants?

Well, in many species
it is certainly the case

that all the individuals are very
closely related to one another.

But that is not so
in the super-colony,

and in some days in June,

such colonies continue
to break the rules.

As midsummer approaches,

the Jura briefly becomes
a paradise of wild flowers.

And something new appears inside
each of the nests - wings.

The royal generation,
male and female,

has finally hatched,
and both will be able to fly.

Winged individuals are the only ones
that are capable of breeding.

The males are little more than
animated insemination devices,

and they will soon achieve
their purpose and die.

But the females,
which are emerging just now,

this is the beginning of a long life
of servitude.

When the weather is just right -
sunny and not too windy -

the nests suddenly become covered
with winged ants.

There's an excitement in the air.

The males,
which have matte black bodies,

are incapable of feeding themselves.

So once they leave the nest they only
have a short time to live.

There's no time to waste.

The virgin queens, who are also black
but splendidly shiny,

have a rather clumsy beginning
to their lives.

They're heavy with fat reserves
and swollen ovaries.

So that getting airborne
is not easy for them.

This is the most important flight
of their lives -

but it's also their first.

Many test their wings
before take-off.

They may need several attempts

before they achieve
complete flight control.

Over a few days, half a million
winged ants of both sexes

take to the air and head off
for new territory.

They then all assemble here,
in the heart of the super-colony.

It's not clear
how they find this meadow,

but year after year,

virgin males and females
from across the super-colony

are drawn here for their
nuptial flight.

The queens congregate in small
patches of taller plants

and begin to release sex pheromones -

airborne chemicals
that attract males.

Detecting this scent on the wind,
the males home in on the females.

The virgin queens may only get
the chance to mate once,

and they need to obtain enough sperm
to fertilise the eggs

they will be producing
for years to come.

But with plenty of males
in the meadow,

they can afford to be choosy.

The males are so driven,

they even try to mate with females
who are already doing so.

Those males fortunate enough
to couple quickly

make the most of their few remaining
hours of life.

Once they've mated,
their service to the colony is over,

and they die of exhaustion.

The queens now have no further use
for their wings,

and they try to get rid of them.

But they are, necessarily,
rather firmly fixed.

Trying to remove a backpack
with your feet,

even if you have six of them,
is clearly a frustrating process.

Eventually, the meadow is marked

with little drifts
of discarded wings.

Such breeding swarms are fairly
typical of ants generally,

but now the queens of the
super-colony

do something much less common.

To understand why they behave
so differently,

we must first return to the spring
battlefields

of the ordinary wood ants outside
the empire of the super-colony.

The warring colonies
on this side of the mountain

have now accepted their frontiers,

and summer brings a brief pause
in their battles.

The mating system they use
may seem at first sight

to be the same as that
of the super-colony

but, in fact,
it's fundamentally different.

Every decision taken by a mated
female is fraught with danger.

The colony this queen comes from is
at war with all its neighbours,

so if she meets any of them,
they will try to kill her.

She needs a home, but she can't
build it without help.

Her solution to the problem is
extraordinary and radical.

Under this rock, a different species,
field ants,

have built a nest.

These small ants, less than a third
of her size, are common,

and live in meadows
on the edge of the forest.

The only way this wood ant queen
can get her own nest

is by taking over one of theirs.

She will become a parasitic queen.

She lurks near the nest,

trying to pick up the scent of
the field ants.

She avoids groups of them,
because they could overpower her.

Instead, she tackles individuals.

There's a brief duel,
and then she retreats.

But each time, she's left with
a trace of their scent,

so that she slowly begins to build up
a chemical disguise.

These contests go on
for several days.

Gradually, her disguise becomes
more and more convincing.

The entrance to the field ants' nest
is unguarded.

Cautiously, she enters.

Inside, she is vastly outnumbered.

Wood ant behaviour
inside a field ant nest

has never been observed in detail
before, let alone filmed,

so what happens next must be
interpreted with caution.

There are fights,
and most wood ant queens

are in fact killed at this stage.

But after she has endured
repeated attacks,

some of the field ants become
less aggressive towards her.

Eventually,
a confused field ant worker

feeds the wood ant queen,
and when it does that,

the fate of the nest is sealed.

The wood ant queen has now acquired
the colony's scent.

She oozes queenly pheromones,

and the field ants seem entranced
by their new foreign queen.

The gamble has paid off, and she has
a fully functioning nest,

ready to receive her first batch
of eggs.

Taking over a nest of field ants

is the way typical wood ants
start a new family.

But how about the queens
from a super-colony,

with their multi-family,
communal nests?

Have they found
a more peaceful strategy?

Each mated female has to set out
on her own journey.

If she's to become a true queen,

she has to find a nest
that will accept her,

and that is where the tolerance of
the members of the super-colony

is tested once again.

Being already in the heart of
a super-colony,

these newly mated queens
don't have to walk far

before encountering their own kind.

But even for a super-colony queen,

walking straight up to a busy trail
is risky.

If the workers she meets
are not in a welcoming mood,

they will tear her to pieces.

Slowly, one by one,
workers come to investigate her.

Some seem uncertain
whether to attack or not,

but others lick and clean her.

After a few tense moments, a worker
starts to drag her towards the nest.

This is a sign
that she will be adopted.

And now scientists have made
a further discovery.

Many nests in the super-colony
shortcut the whole process.

The winged males and the queen ants
don't even bother to leave the nest.

Many different families live here,

so there's no need to fly away
to avoid inbreeding.

The winged queens can simply mate

with one of the males
that hatched here.

Perhaps this unusual behaviour
is the next stage

in the evolution of the super-colony.

With these innovative mating systems,

the super-colony queens
don't take the same risks

as normal wood ant queens.

They don't need to infiltrate
the nest of field ants

to start a family.

The workers just build new nests
when needed,

enabling the super-colony
to extend deep into the forest

where there are no field ants.

It's changes in behaviour like this

that most likely gave rise to the
super-colony in the first place,

and colonised this new habitat
with all its riches.

It's possible that
this kind of cooperation

between different nests is becoming
more common among ants.

New super-colonies
are still being discovered

in different species
across the world.

Are we perhaps witnessing
the next stage of

the social conquest of the Earth?

The super-colony consists of
literally thousands of

different families,
all working in cooperation.

It's a development that mankind
achieved a very long time ago,

and could be seen
as one of the reasons why

we have come to dominate
so many parts of the planet.

Could it be that peace
is the winning strategy

on this ant mountain too?