All language subtitles for David.Attenboroughs.Ant.Mountain.2017.1080p.WEB.H264-GRASHOPR_track3_[eng]

[soft expectant music]

- 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're 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 recognized
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.

[dramatic expectant music]

[bird cawing]

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 will be looking
at the differences

between these two
wood ant societies,

one that wages war
with all its neighbors,

and the other which welcomes
them and lives at peace.

[soft thoughtful music]

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.

[soft thoughtful music]

The ants survived 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're recharging
their batteries,

absorbing heat directly
from the sun's rays.

[dramatic expectant music]

This behavior 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.

[soft expectant music]

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 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.
[soft expectant music]

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.

[soft uneasy music]

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.

[soft thoughtful music]

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.

[soft thoughtful music]

It's now early April.

The queens' return 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.
[soft thoughtful music]

Using infrared light, which
is invisible to the ants,

we can watch them inside their
nest without disturbing them.

[soft thoughtful
music continues]

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 a 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 is 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.

[soft expectant music]

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.

[soft thoughtful music]

Spring is now well on the way.

The snow has disappeared, and
color comes to the meadows.

[gentle thoughtful music]

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

and the first
larvae are hatching.

The workers labor
unceasingly to ensure

that the growing brood
will be ready to emerge

in six weeks' time, at the
peak of the short Jura summer.

[gentle thoughtful music]

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 colonists 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 reestablished.

And in order to do that,
workers from both nests

are now scouring the ground,

and that brings neighboring
ants into contact

for the first time this season.

[dramatic expectant music]

When foragers from the
different nests meet,

they immediately recognize that
they're from rival families.

They then dash back
to their nests,

and within minutes
both colonies know

the territory on their
frontier is being disputed.

Armies assemble.
[dramatic expectant music]

This is war, and the weapons
being used are chemical.

Formic acid [sniffing], I
can smell it in the air.

They're squirting it from
the end 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.

[dramatic expectant music]

As they grapple, each tries
to restrain its opponent

by clamping its jaws
around a leg or an antenna.

[dramatic expectant
music continues]

Soldiers from both sides tug
at their opponents' limbs.

[dramatic expectant
music continues]

It could 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.

[dramatic expectant music]

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?

[dramatic expectant music]

The smell of formic
acid reaches the colony,

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

[soft dramatic music]
[birds chattering]

These wars can continue
for over a week.

At their peak many
thousands are fighting,

and thousands are killed.
[soft dramatic music]

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, will be
savagely attacked.

But let's see what happens.

[soft expectant music]
[birds chattering]

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 behavior, 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's 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.

[soft thoughtful music]

Because of this,
super-colony ants

can move freely between mounds,

and they have as a result

created over a hundred
kilometers 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.

[soft thoughtful music]

It comes from the spruce trees.

[soft thoughtful
music continues]

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

They 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 sap,

and excrete what they don't need

as a sugary liquid called
honeydew, and the ants love it.

[gentle thoughtful music]

Just as human farmers
milk their cows,

so the ants stroke the
aphids with their antennae,

to persuade them to
release their honeydew.

[gentle thoughtful
music continues]

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.

[bright thoughtful music]

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 the eggs are far less
likely to be infected by fungi.

[wind whooshing]
[birds chattering]

This immense, peaceful
super-colony has few enemies,

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

[cowbells clanking]
[cows mooing]

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.

[cows mooing]
[cowbells clanking]

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.

[cows mooing]
[dramatic expectant music]

But these ants are
very determined.

When one squirts it's
acid, others follow suit.

[dramatic expectant
music continues]

The result is a
coordinated barrage.

[acid splattering]
[soft dramatic music]

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.

[cows mooing]
[cowbells clanking]

[insects chewing]

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 labor 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.
[bee buzzing]

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.

[soft expectant music]

The ants spread
out from the nest,

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

[soft expectant music]
[bee buzzing]

As the hunters approach,
those that can take flight.

[bee buzzing]
[wings fluttering]

And 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.

[soft expectant music]

She's carrying a little
sac full of eggs.

[soft expectant music continues]

She decides to run for it,

and her sudden movement
alerts the hunters.

[soft dramatic music]

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.

[soft expectant music]

Slow motion reveals the
basic ant hunting technique,

lunge with jaws open
and hope for the best.

[dramatic expectant music]

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.
[dramatic tense music]

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.

[tense expectant music]

A super-colony can make
hundreds of millions

of kills every year.

Beetles, caterpillars,
worms, flies,

they will tackle almost
any living thing.

[tense expectant
music continues]

Whatever the prey,
it's first cut up

and eaten by the workers,
who then regurgitate it

to feed to the larvae.

[insects chewing]

Once they have
grown to full size,

the larvae spins silk
cocoons for themselves.

Inside each a featureless larva
is changing into an adult,

their time in the
sun is approaching.

[soft thoughtful music]

Wood ants live in one of
the most highly-organized

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.

[bright expectant music]

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
booth 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.

[gentle thoughtful music]

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.

[gentle expectant music]

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 takeoff.

They may need several attempts

before they achieve
complete flight control.

[thoughtful expectant music]

Over a few days, half
a million winged ants

of both sexes take the air and
head off for new territory.

[bright dramatic music]

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.

[bright dramatic music]

The queens congregate in
small patches of taller plants

and begin to release
sex pheromones,

airborne chemicals
that attract males.

[bright dramatic
music continues]

Detecting this
scent on the wind,

the males home in
on the females.

[bright dramatic
music continues]

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

and they need to obtain enough
sperm to fertilize 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.

[bright dramatic music]

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.

[soft thoughtful music]

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.

[soft expectant music]

Trying to remove a
backpack with your feet,

even if you have six of them,

is clearly a
frustrating process.

[soft expectant music continues]

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.

[soft thoughtful music]

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 neighbors.

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.

[soft expectant music]

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.

[soft expectant music]

The entrance to the field
ants' nest is unguarded.

Cautiously, she enters.

Inside, she is
vastly outnumbered.

Wood ant behavior
inside a field ant nest

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

So what happens next must
be interpreted with caution.

[dramatic expectant music]

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 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 multifamily,
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.

[soft expectant music]
[birds chattering]

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

Some seem uncertain
whether to attack or not,

but others lick and clean her.
[soft expectant music]

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
behavior is the next stage

in the evolution of
the super-colony.

[bright expectant music]

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
behavior like this

that most likely gave rise

to the super colony
in the first place,

and colonized 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?

[bright dramatic music]