Attenborough and the Empire of the Ants

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0:00:11 > 0:00:12The Jura Mountains

0:00:12 > 0:00:14on the French-Swiss border

0:00:14 > 0:00:16are in the grip of winter.

0:00:16 > 0:00:20The ground has been frozen solid for months.

0:00:20 > 0:00:23This is a tough place in which to live.

0:00:24 > 0:00:31I'm told that clearings like these could be the home of a real giant.

0:00:31 > 0:00:34At this time of the year, it'll be in hiding.

0:00:38 > 0:00:42But evidence of its existence - these strange mounds -

0:00:42 > 0:00:43is everywhere.

0:00:45 > 0:00:49Inside here, deep down and protected

0:00:49 > 0:00:52from the cold, the giant is asleep.

0:00:54 > 0:00:57Beneath the thatch of spruce needles

0:00:57 > 0:01:00lies a maze of tunnels and chambers -

0:01:00 > 0:01:03the home of hibernating wood ants.

0:01:03 > 0:01:05Individually, they are tiny,

0:01:05 > 0:01:09but they're members of a giant super-colony.

0:01:12 > 0:01:17When temperatures rise, over half a billion of them will emerge

0:01:17 > 0:01:19and dominate this landscape.

0:01:23 > 0:01:28Scientists are only just working out how ants manage to survive up here.

0:01:28 > 0:01:32But in fact there's a much greater and more profound mystery

0:01:32 > 0:01:35that has brought me up this mountain.

0:01:37 > 0:01:41Among ants, co-operation between colonies is very rare.

0:01:41 > 0:01:43Warfare is common.

0:01:44 > 0:01:50Yet these nests over a great area live at peace with one another.

0:01:53 > 0:01:58This may sound like an epic tale of war and peace

0:01:58 > 0:02:03but does it also contain an echo of human nature?

0:02:04 > 0:02:07These ants, in some extraordinary way,

0:02:07 > 0:02:10have exchanged war for peace.

0:02:10 > 0:02:12It's now recognised

0:02:12 > 0:02:16as one of the largest of all insect super-societies,

0:02:16 > 0:02:21and its very existence conflicts with some of the laws of evolution

0:02:21 > 0:02:23as we presently understand them.

0:02:35 > 0:02:41It's been a long, cold winter here in the Swiss Jura Mountains.

0:02:44 > 0:02:46It's hard to believe

0:02:46 > 0:02:51that any insect could survive in this frozen landscape.

0:02:51 > 0:02:53But now change is in the air.

0:02:57 > 0:03:02Soon, ant nests all over this mountain will come to life.

0:03:02 > 0:03:06Some of these mounds are independent colonies

0:03:06 > 0:03:10but others are part of one huge super-colony.

0:03:11 > 0:03:15Over the coming months, I'll be looking at the differences

0:03:15 > 0:03:18between these two wood ant societies -

0:03:18 > 0:03:20one that wages war with all its neighbours,

0:03:20 > 0:03:25and the other, which welcomes them and lives at peace.

0:03:34 > 0:03:36As the grip of winter eases,

0:03:36 > 0:03:40sentries emerge from the mounds to check on conditions.

0:03:46 > 0:03:50They detect the sign that they've been waiting for -

0:03:50 > 0:03:52the temperatures are rising.

0:03:54 > 0:03:56Spring is on the way.

0:04:05 > 0:04:11The ants survive the winter thanks to their own central-heating system,

0:04:11 > 0:04:15warmth given off by the slow decomposition of the dead vegetation

0:04:15 > 0:04:18in the nest's fabric,

0:04:18 > 0:04:21and that prevented them all from freezing.

0:04:24 > 0:04:27Now, by swarming all over the surface of the nest,

0:04:27 > 0:04:29they are recharging their batteries,

0:04:29 > 0:04:33absorbing heat directly from the sun's rays.

0:04:46 > 0:04:52This behaviour only happens over one or two days in the early spring.

0:04:52 > 0:04:56The worker ants have emerged into the sunshine

0:04:56 > 0:04:58and are now clumping together.

0:04:58 > 0:05:01And they're not just sunbathing.

0:05:01 > 0:05:05It could well be that the ultraviolet rays of the sun

0:05:05 > 0:05:08cure them of any infections from viruses or fungi

0:05:08 > 0:05:12that may have happened during their long sleep underground.

0:05:16 > 0:05:19You can almost feel the enthusiasm

0:05:19 > 0:05:24with which these little creatures are enjoying their sunbathe.

0:05:32 > 0:05:38This is unusual enough but now here is something truly extraordinary.

0:05:38 > 0:05:41There is a queen.

0:05:43 > 0:05:47She's almost twice the size of her subjects.

0:05:49 > 0:05:52She's also the most important member of her family.

0:05:53 > 0:05:55And what's more, there's another.

0:05:55 > 0:06:00To see a queen exposed and vulnerable outside the nest

0:06:00 > 0:06:02is very rare indeed.

0:06:02 > 0:06:04There's one.

0:06:08 > 0:06:10And there's another...

0:06:10 > 0:06:12..shining wonderfully in the sunshine.

0:06:13 > 0:06:18A normal wood ant nest usually has just a single queen

0:06:18 > 0:06:22who lays all the eggs - but clearly this is not so here.

0:06:24 > 0:06:28There's another. There's another. Several of them.

0:06:28 > 0:06:30Amazing.

0:06:39 > 0:06:41After a few moments in the sunshine -

0:06:41 > 0:06:44the only time they see daylight in the whole year -

0:06:44 > 0:06:46the queens disappear

0:06:46 > 0:06:51and make their way back to the chambers deep in the nest.

0:06:59 > 0:07:02Those unwilling to go are dragged back.

0:07:02 > 0:07:06We may call them queens but there's no sovereign rule here.

0:07:06 > 0:07:08The workers govern by consensus,

0:07:08 > 0:07:12and they decide when and where the queens will go.

0:07:21 > 0:07:24There may be hundreds of queens in this single nest,

0:07:24 > 0:07:29and there over a thousand such mounds as this, all interconnected.

0:07:31 > 0:07:34So, across the super-colony

0:07:34 > 0:07:37there may be as many as a million queens.

0:07:45 > 0:07:48It's now early April.

0:07:48 > 0:07:52The queens' return below to prepare for the egg-laying

0:07:52 > 0:07:54started a race against the clock.

0:07:54 > 0:07:58They must complete their most important work below

0:07:58 > 0:08:00in the next two months.

0:08:05 > 0:08:08Using infrared light, which is invisible to the ants,

0:08:08 > 0:08:12we can watch them inside their nest without disturbing them.

0:08:18 > 0:08:20Most of the first eggs to be laid

0:08:20 > 0:08:24will produce the next generation of breeding individuals -

0:08:24 > 0:08:26the queens and the males -

0:08:26 > 0:08:29both of whom will have wings.

0:08:31 > 0:08:35Inside the thousand nests of the super-colony,

0:08:35 > 0:08:39over half a billion mostly unrelated worker ants

0:08:39 > 0:08:43co-operate to make sure that the queens and the males will be ready

0:08:43 > 0:08:46for their mating flights in mid-June.

0:08:52 > 0:08:56With all these developments on the way, it's imperative

0:08:56 > 0:09:00that the workers collect more food as soon as possible.

0:09:03 > 0:09:06But many of the mounds are still surrounded by snow...

0:09:07 > 0:09:11..so the workers can't reach their feeding grounds.

0:09:16 > 0:09:19But there's something they can collect -

0:09:19 > 0:09:20heat.

0:09:23 > 0:09:25The nest needs more heat

0:09:25 > 0:09:29than that which comes from the rotting vegetation

0:09:29 > 0:09:33if the eggs are to hatch in time for their June appointment.

0:09:37 > 0:09:42Now, however, the ants have another source of warmth.

0:09:48 > 0:09:51Using their bodies as solar panels,

0:09:51 > 0:09:53the ants harvest the sunlight.

0:09:56 > 0:10:01We have a heat-sensitive camera that detects differences in temperature.

0:10:01 > 0:10:04The nest appears black

0:10:04 > 0:10:07because it's hotter than the surrounding environment.

0:10:10 > 0:10:13It shows a similar difference in the ants.

0:10:17 > 0:10:19Those going down into the nest are black

0:10:19 > 0:10:22because they've been heated by the sun,

0:10:22 > 0:10:25whereas those coming out are white because they're cold,

0:10:25 > 0:10:29having transferred their body heat to their charges

0:10:29 > 0:10:31in the chambers below.

0:10:36 > 0:10:39It's this kind of selfless collaboration

0:10:39 > 0:10:42that is the key to success of any ant colony.

0:10:49 > 0:10:51In normal ant colonies,

0:10:51 > 0:10:56all the workers are related to one another and to the queen,

0:10:56 > 0:11:00and the theory is that that is why they all co-operate.

0:11:00 > 0:11:03But that is not the case here.

0:11:03 > 0:11:06There are hundreds of queens here.

0:11:06 > 0:11:09Over one thousand have been counted in a single nest,

0:11:09 > 0:11:12so all the workers can't have the same parents -

0:11:12 > 0:11:15and genetics have confirmed that this is so.

0:11:16 > 0:11:21It's this co-operation between unrelated ants in a single colony

0:11:21 > 0:11:25that appears to be rewriting the rules of insect evolution,

0:11:25 > 0:11:28but we still don't really know how this has come about.

0:11:34 > 0:11:38Spring is now well on the way.

0:11:41 > 0:11:43The snow has disappeared,

0:11:43 > 0:11:46and colour comes to the meadows.

0:12:00 > 0:12:03By late April, there are piles of eggs in the nest

0:12:03 > 0:12:06and the first larvae are hatching.

0:12:11 > 0:12:16The workers labour unceasingly to ensure that the growing brood

0:12:16 > 0:12:19will be ready to emerge in six weeks' time,

0:12:19 > 0:12:22at the peak of the short Jura summer.

0:12:38 > 0:12:42But not every ant nest on this mountain can be so focused.

0:12:42 > 0:12:47Some will soon have to deal with threats to their very survival.

0:12:49 > 0:12:51Just a short distance away,

0:12:51 > 0:12:54on the borders of the super-colony's woodland territory,

0:12:54 > 0:12:56there are other wood ants.

0:12:59 > 0:13:04The mounds here on this side of the mountain look exactly the same

0:13:04 > 0:13:07as those of the super-colony,

0:13:07 > 0:13:09and so do the ants themselves.

0:13:13 > 0:13:16The inhabitants of each nest here are all the offspring

0:13:16 > 0:13:19of its single queen,

0:13:19 > 0:13:22and the colonies compete aggressively with one another.

0:13:29 > 0:13:31After the winter hibernation,

0:13:31 > 0:13:36the territories between that nest over there and this one here

0:13:36 > 0:13:41have become blurred, and the frontier has to be re-established.

0:13:41 > 0:13:43And in order to do that,

0:13:43 > 0:13:47workers from both nests are now scouring the ground,

0:13:47 > 0:13:50and that brings neighbouring ants

0:13:50 > 0:13:53into contact for the first time this season.

0:13:58 > 0:14:01When foragers from the different nests meet,

0:14:01 > 0:14:05they immediately recognise that they're from rival families.

0:14:07 > 0:14:11They then dash back to their nests and within minutes both colonies

0:14:11 > 0:14:15know that territory on their frontier is being disputed.

0:14:18 > 0:14:20Armies assemble.

0:14:43 > 0:14:46This...is war.

0:14:46 > 0:14:49And the weapons being used are chemical.

0:14:49 > 0:14:51Formic acid.

0:14:51 > 0:14:53I can smell it in the air.

0:14:53 > 0:14:57They're squirting it from the ends of their abdomen,

0:14:57 > 0:15:00and if they can bite their opponents

0:15:00 > 0:15:05so that the formic acid gets beneath the outer shell of an ant,

0:15:05 > 0:15:08it will dissolve its internal organs.

0:15:15 > 0:15:19As they grapple, each tries to restrain its opponent

0:15:19 > 0:15:23by clamping its jaws around a leg or an antenna.

0:15:30 > 0:15:34Soldiers from both sides tug at their opponents' limbs.

0:15:44 > 0:15:48It can take seven ants to subdue a single enemy.

0:15:53 > 0:15:55One holds each leg,

0:15:55 > 0:15:57and the seventh uses its mandibles

0:15:57 > 0:16:01to cut open sections of their opponent's exoskeleton,

0:16:01 > 0:16:03exposing the insides.

0:16:05 > 0:16:08An attacker brings forward its abdomen under its body

0:16:08 > 0:16:11and squirts acid onto its victim.

0:16:16 > 0:16:18Battles are going on everywhere.

0:16:25 > 0:16:30Each colony carries its own chemical badge, invisible to our eyes

0:16:30 > 0:16:33but clear to the ants' sensitive antennae.

0:16:33 > 0:16:36Fighters touch each other to confirm whose side they're on.

0:16:44 > 0:16:48Here and there, individuals clamber up the vegetation.

0:16:52 > 0:16:53Are they having a rest,

0:16:53 > 0:16:57or are they surveying progress to see where help is needed?

0:17:12 > 0:17:15The smell of formic acid reaches the colony,

0:17:15 > 0:17:20and more ants from both sides run to join the battle.

0:17:36 > 0:17:39These wars can continue for over a week.

0:17:39 > 0:17:44At their peak, many thousands are fighting and thousands are killed.

0:18:06 > 0:18:10The victors will certainly have enlarged their territory...

0:18:11 > 0:18:15..but some say they have also gained other rewards.

0:18:17 > 0:18:21They're taking off the bodies of their victims

0:18:21 > 0:18:25and carrying them back to the nest over there to feast upon them.

0:18:33 > 0:18:37Both sides have suffered heavy losses.

0:18:41 > 0:18:45For the ants in the meadow, it has been a costly start to the year.

0:18:56 > 0:18:59Higher up the mountain, in the territory of the super-colony,

0:18:59 > 0:19:04the inhabitants of different nests are also meeting.

0:19:04 > 0:19:07But here, things are very different.

0:19:08 > 0:19:14These ants come from a mound about half a mile away.

0:19:14 > 0:19:18If that mound was a separate, independent colony,

0:19:18 > 0:19:21then these, when they land there,

0:19:21 > 0:19:24would be savagely attacked.

0:19:24 > 0:19:26But let's see what happens.

0:19:39 > 0:19:43At first, the resident ant makes an aggressive gesture.

0:19:48 > 0:19:53But then the other strokes the first's antennae.

0:19:53 > 0:19:58That gesture is a request for food, and the other obligingly feeds her.

0:20:02 > 0:20:05This behaviour - known as trophallaxis -

0:20:05 > 0:20:07is in itself not unusual.

0:20:07 > 0:20:10Most ants do it at times.

0:20:10 > 0:20:15What is unique is that these ants are almost certainly unrelated,

0:20:15 > 0:20:18yet they treat each other as if they were from the same nest.

0:20:21 > 0:20:25They do this because they share the super-colony scent,

0:20:25 > 0:20:29a chemical signature that is transferred together with the food.

0:20:36 > 0:20:40In one experiment, scientists fed a distinctive chemical to a nest

0:20:40 > 0:20:42on one side of the super-colony,

0:20:42 > 0:20:46and eight weeks later that same chemical appeared

0:20:46 > 0:20:49far away on the other side.

0:20:54 > 0:20:58It's this sharing of food between over half a billion individuals

0:20:58 > 0:21:03that makes this super-society so truly remarkable.

0:21:12 > 0:21:17Because of this, super-colony ants can move freely between mounds,

0:21:17 > 0:21:19and they have, as a result,

0:21:19 > 0:21:22created over 100km of trails

0:21:22 > 0:21:25that link over 1,000 nests.

0:21:29 > 0:21:33These trails not only allow the ants to make new nests

0:21:33 > 0:21:34deep in the forest,

0:21:34 > 0:21:37they also give all the members of the super-colony

0:21:37 > 0:21:40access to resources of great value to them.

0:21:46 > 0:21:49It comes from the spruce trees.

0:22:07 > 0:22:11The ants don't feed directly on the spruce trees.

0:22:11 > 0:22:13They become farmers.

0:22:13 > 0:22:16And these...are their flocks.

0:22:16 > 0:22:17Aphids.

0:22:19 > 0:22:23The presence of the ants keeps insect predators at bay

0:22:23 > 0:22:27so the aphids can feed unmolested.

0:22:27 > 0:22:29They drink the tree's sap

0:22:29 > 0:22:35and excrete what they don't need as a sugary liquid called honeydew.

0:22:35 > 0:22:37And the ants love it.

0:22:46 > 0:22:49Just as human farmers milk their cows,

0:22:49 > 0:22:52so the ants stroke the aphids with their antennae

0:22:52 > 0:22:55to persuade them to release their honeydew.

0:23:05 > 0:23:07Once the aphids are milked

0:23:07 > 0:23:11and the ants have drunk as much honeydew as they can carry,

0:23:11 > 0:23:17they head down the tree, abdomens bulging, and return to the nest.

0:23:24 > 0:23:29The honeydew is not only food with which to sustain themselves.

0:23:29 > 0:23:33Some use it to raise the heat of their bodies well above normal,

0:23:33 > 0:23:36and so warm the atmosphere within the nest -

0:23:36 > 0:23:40a valuable ability in the fickle climate of the Jura.

0:23:41 > 0:23:45The spruce trees themselves also produce a substance

0:23:45 > 0:23:48that the ants can use directly.

0:23:52 > 0:23:58These ants have collected little flakes of resin.

0:23:58 > 0:24:01That's a sort of gum that oozes from the broken twig

0:24:01 > 0:24:04of a coniferous tree.

0:24:04 > 0:24:08The tree uses it to seal off an injury.

0:24:08 > 0:24:11But what are the ants using it for?

0:24:14 > 0:24:19Inside the nest, the extra warmth produced by honeydew

0:24:19 > 0:24:21helps the queens to keep laying

0:24:21 > 0:24:23and the larvae to keep growing.

0:24:29 > 0:24:34However, constant warmth can create problems.

0:24:34 > 0:24:38Despite regular cleaning, diseases can thrive.

0:24:41 > 0:24:45The ants have a remarkable solution to that problem.

0:24:50 > 0:24:54They cover the surface of the mounds with tiny nuggets of resin,

0:24:54 > 0:24:58and also take it into the chambers below.

0:24:58 > 0:25:02One nest contained over four kilos of it.

0:25:02 > 0:25:05It is, in fact, ant medicine.

0:25:08 > 0:25:12The ants combine acid from their bodies with the resin

0:25:12 > 0:25:15and so produce a very effective antibiotic.

0:25:15 > 0:25:19This is one of the most sophisticated animal pharmacologies

0:25:19 > 0:25:21known to science.

0:25:23 > 0:25:28It's been shown that wood ants living in nests that contain resin

0:25:28 > 0:25:33are better able to survive diseases than those that don't,

0:25:33 > 0:25:37and their eggs are far less likely to be infected by fungi.

0:25:44 > 0:25:49This immense, peaceful super-colony has few enemies.

0:25:49 > 0:25:53But now, at the end of May, a new threat has arrived.

0:25:55 > 0:25:58BELL JANGLES

0:25:58 > 0:26:00COW MOOS

0:26:03 > 0:26:08The Jura is famous for producing some of Europe's finest cheese.

0:26:13 > 0:26:17For generations, farmers have made small clearings in the woods

0:26:17 > 0:26:20to create meadows where cattle can graze.

0:26:25 > 0:26:26Only now is it warm enough

0:26:26 > 0:26:31for cows to be brought up to these high pastures.

0:26:37 > 0:26:42Somehow, the ants need to make sure that they're left alone,

0:26:42 > 0:26:45and that nothing damages their nests.

0:26:46 > 0:26:49And that's a considerable challenge, even for a super-colony.

0:27:02 > 0:27:05But these ants are very determined.

0:27:05 > 0:27:09When one squirts its acid, others follow suit.

0:27:17 > 0:27:21The result is a co-ordinated barrage.

0:27:33 > 0:27:36The cows are not harmed, but they do get a dose of acid in the nose -

0:27:36 > 0:27:38which they don't like -

0:27:38 > 0:27:42and they tend thereafter to avoid these mounds.

0:28:02 > 0:28:07By now, in June, the larvae have become big and greedy.

0:28:07 > 0:28:10They must be given special care

0:28:10 > 0:28:13because they will produce the next generation of royalty,

0:28:13 > 0:28:16so the workers labour hard to meet their demands.

0:28:18 > 0:28:23In summer, hundreds of thousands of eggs are hatching every day,

0:28:23 > 0:28:26and honeydew is not enough.

0:28:26 > 0:28:31The ants go in search of something else. A supplement.

0:28:31 > 0:28:33Fresh meat.

0:28:37 > 0:28:40The lush green hills and mountains of the Jura

0:28:40 > 0:28:42are now teeming with all sorts of life,

0:28:42 > 0:28:46and nearly all of it is potential food.

0:29:05 > 0:29:08The ants spread out from the nest,

0:29:08 > 0:29:12scouring every square inch of ground in search of prey.

0:29:23 > 0:29:27As the hunters approach, those that can, take flight.

0:29:39 > 0:29:42The ants' vision is not very acute.

0:29:42 > 0:29:44They can only see a target if it moves.

0:29:49 > 0:29:53A wolf spider, however, can see the ants clearly.

0:29:53 > 0:29:58But as long as she doesn't move, they won't know that she's here.

0:30:09 > 0:30:12She's carrying a little sack full of eggs.

0:30:30 > 0:30:34She decides to run for it, and her sudden movement alerts the hunters.

0:30:54 > 0:30:59That first fleeting touch by an ant left a faint scent mark,

0:30:59 > 0:31:03and now fellow hunters can home in on their target.

0:31:07 > 0:31:11The spider has a venomous bite, but that is no use now.

0:31:11 > 0:31:14Eight powerful legs are her only hope,

0:31:14 > 0:31:18but her speed is the very thing that enables the ants to follow her.

0:31:26 > 0:31:29Slow motion reveals the basic ant-hunting technique -

0:31:29 > 0:31:33lunge with jaws open and hope for the best.

0:31:46 > 0:31:49At last, an ant manages to grab her.

0:31:54 > 0:31:58Like a pride of lions taking down a buffalo, the ants surround her.

0:31:58 > 0:32:00Two restrain their catch,

0:32:00 > 0:32:03while another delivers the flesh-dissolving acid.

0:32:18 > 0:32:22The wolf spider is just one of many victims.

0:32:34 > 0:32:37Alone, an ant can take only the smallest prey.

0:32:37 > 0:32:40But by working as a team,

0:32:40 > 0:32:43they can capture creatures many times their size.

0:33:00 > 0:33:06A super-colony can make hundreds of millions of kills every year.

0:33:08 > 0:33:11Beetles, caterpillars, worms, flies -

0:33:11 > 0:33:14they will tackle almost any living thing.

0:33:36 > 0:33:40Whatever the prey, it's first cut up and eaten by the workers,

0:33:40 > 0:33:43who then regurgitate it to feed to the larvae.

0:33:53 > 0:33:56Once they have grown to full size,

0:33:56 > 0:34:00the larvae spin silk cocoons for themselves.

0:34:08 > 0:34:13Inside each, a featureless larva is changing into an adult.

0:34:13 > 0:34:16Their time in the sun is approaching.

0:34:33 > 0:34:37Wood ants live in one of the most highly organised

0:34:37 > 0:34:40and complex of insect societies.

0:34:40 > 0:34:42They fight wars over territory,

0:34:42 > 0:34:46they hunt in packs, and farm other species.

0:34:46 > 0:34:49They build complex homes with central heating,

0:34:49 > 0:34:52they produce their own medicine,

0:34:52 > 0:34:58and one group of them, we now know, has made another advance.

0:34:58 > 0:35:03The super-colony has extended this collaboration beyond the frontiers

0:35:03 > 0:35:08of the family to form a super-society of such dimensions

0:35:08 > 0:35:11that we can perhaps begin to compare it with that other

0:35:11 > 0:35:16great social creature on this planet - ourselves.

0:35:16 > 0:35:21People studying the origins of human culture suggest that shared myths

0:35:21 > 0:35:26were one of the factors that bound early human societies together.

0:35:26 > 0:35:28But what about ants?

0:35:28 > 0:35:32Well, in many species it is certainly the case

0:35:32 > 0:35:37that all the individuals are very closely related to one another.

0:35:37 > 0:35:41But that is not so in the super-colony,

0:35:41 > 0:35:44and in some days in June,

0:35:44 > 0:35:48such colonies continue to break the rules.

0:35:53 > 0:35:56As midsummer approaches,

0:35:56 > 0:36:00the Jura briefly becomes a paradise of wild flowers.

0:36:04 > 0:36:10And something new appears inside each of the nests - wings.

0:36:15 > 0:36:18The royal generation, male and female,

0:36:18 > 0:36:22has finally hatched and both will be able to fly.

0:36:24 > 0:36:29Winged individuals are the only ones that are capable of breeding.

0:36:29 > 0:36:33The males are little more than animated insemination devices,

0:36:33 > 0:36:36and they will soon achieve their purpose and die.

0:36:36 > 0:36:40But the females, which are emerging just now,

0:36:40 > 0:36:45this is the beginning of a long life of servitude.

0:36:52 > 0:36:56When the weather is just right - sunny and not too windy -

0:36:56 > 0:37:00the nests suddenly become covered with winged ants.

0:37:00 > 0:37:02There's an excitement in the air.

0:37:15 > 0:37:17The males, which have matte black bodies,

0:37:17 > 0:37:21are incapable of feeding themselves.

0:37:21 > 0:37:24So once they leave the nest they only have a short time to live.

0:37:24 > 0:37:26There's no time to waste.

0:37:29 > 0:37:32The virgin queens, who are also black but splendidly shiny,

0:37:32 > 0:37:36have a rather clumsy beginning to their lives.

0:37:37 > 0:37:41They're heavy with fat reserves and swollen ovaries.

0:37:43 > 0:37:46So getting airborne is not easy for them.

0:37:49 > 0:37:52This is the most important flight of their lives -

0:37:52 > 0:37:54but it's also their first.

0:37:57 > 0:38:00Many test their wings before takeoff.

0:38:03 > 0:38:05They may need several attempts

0:38:05 > 0:38:09before they achieve complete flight control.

0:38:22 > 0:38:26Over a few days, half a million winged ants of both sexes

0:38:26 > 0:38:31take to the air and head off for new territory.

0:38:47 > 0:38:52They then all assemble here, in the heart of the super-colony.

0:38:54 > 0:39:01It's not clear how they find this meadow but, year after year,

0:39:01 > 0:39:05virgin males and females from across the super-colony

0:39:05 > 0:39:09are drawn here for their nuptial flight.

0:39:23 > 0:39:26The queens congregate in small patches of taller plants

0:39:26 > 0:39:29and begin to release sex pheromones -

0:39:29 > 0:39:32airborne chemicals that attract males.

0:39:43 > 0:39:48Detecting this scent on the wind, the males home in on the females.

0:40:01 > 0:40:05The virgin queens may only get the chance to mate once,

0:40:05 > 0:40:09and they need to obtain enough sperm to fertilise the eggs

0:40:09 > 0:40:12they will be producing for years to come.

0:40:15 > 0:40:17But with plenty of males in the meadow,

0:40:17 > 0:40:19they can afford to be choosy.

0:40:23 > 0:40:24The males are so driven,

0:40:24 > 0:40:28they even try to mate with females who are already doing so.

0:40:47 > 0:40:50Those males fortunate enough to couple quickly

0:40:50 > 0:40:54make the most of their few remaining hours of life.

0:40:59 > 0:41:02Once they've mated, their service to the colony is over,

0:41:02 > 0:41:04and they die of exhaustion.

0:41:15 > 0:41:19The queens now have no further use for their wings,

0:41:19 > 0:41:21and they try to get rid of them.

0:41:24 > 0:41:28But they are, necessarily, rather firmly fixed.

0:41:36 > 0:41:39Trying to remove a backpack with your feet,

0:41:39 > 0:41:43even if you have six of them, is clearly a frustrating process.

0:42:09 > 0:42:12Eventually, the meadow is marked

0:42:12 > 0:42:16with little drifts of discarded wings.

0:42:20 > 0:42:24Such breeding swarms are fairly typical of ants generally,

0:42:24 > 0:42:27but now the queens of the super-colony

0:42:27 > 0:42:30do something much less common.

0:42:35 > 0:42:38To understand why they behave so differently,

0:42:38 > 0:42:41we must first return to the spring battlefields

0:42:41 > 0:42:45of the ordinary wood ants outside the empire of the super-colony.

0:42:53 > 0:42:55The warring colonies on this side of the mountain

0:42:55 > 0:42:58have now accepted their frontiers,

0:42:58 > 0:43:03and summer brings a brief pause in their battles.

0:43:03 > 0:43:07The mating system they use may seem at first sight

0:43:07 > 0:43:11to be the same as that of the super-colony but, in fact,

0:43:11 > 0:43:13it's fundamentally different.

0:43:13 > 0:43:19Every decision taken by a mated female is fraught with danger.

0:43:25 > 0:43:31The colony this queen comes from is at war with all its neighbours,

0:43:31 > 0:43:34so if she meets any of them, they will try to kill her.

0:43:34 > 0:43:39She needs a home, but she can't build it without help.

0:43:41 > 0:43:46Her solution to the problem is extraordinary and radical.

0:43:54 > 0:43:59Under this rock, a different species, field ants,

0:43:59 > 0:44:01have built a nest.

0:44:03 > 0:44:08These small ants, less than a third of her size, are common,

0:44:08 > 0:44:11and live in meadows on the edge of the forest.

0:44:12 > 0:44:16The only way this wood ant queen can get her own nest

0:44:16 > 0:44:20is by taking over one of theirs.

0:44:23 > 0:44:26She will become a parasitic queen.

0:44:29 > 0:44:32She lurks near the nest,

0:44:32 > 0:44:35trying to pick up the scent of the field ants.

0:44:36 > 0:44:41She avoids groups of them, because they could overpower her.

0:44:41 > 0:44:45Instead, she tackles individuals.

0:44:45 > 0:44:49There's a brief duel, and then she retreats.

0:44:50 > 0:44:54But each time, she's left with a trace of their scent,

0:44:54 > 0:44:58so that she slowly begins to build up a chemical disguise.

0:45:01 > 0:45:05These contests go on for several days.

0:45:07 > 0:45:12Gradually, her disguise becomes more and more convincing.

0:45:20 > 0:45:24The entrance to the field ants' nest is unguarded.

0:45:26 > 0:45:28Cautiously, she enters.

0:45:34 > 0:45:37Inside, she is vastly outnumbered.

0:45:40 > 0:45:42Wood ant behaviour inside a field ant nest

0:45:42 > 0:45:46has never been observed in detail before, let alone filmed,

0:45:46 > 0:45:50so what happens next must be interpreted with caution.

0:46:00 > 0:46:03There are fights, and most wood ant queens

0:46:03 > 0:46:05are in fact killed at this stage.

0:46:10 > 0:46:14But after she has endured repeated attacks,

0:46:14 > 0:46:17some of the field ants become less aggressive towards her.

0:46:21 > 0:46:24Eventually, a confused field ant worker

0:46:24 > 0:46:28feeds the wood ant queen, and when it does that,

0:46:28 > 0:46:31the fate of the nest is sealed.

0:46:33 > 0:46:37The wood ant queen has now acquired the colony's scent.

0:46:37 > 0:46:40She oozes queenly pheromones,

0:46:40 > 0:46:45and the field ants seem entranced by their new foreign queen.

0:46:47 > 0:46:51The gamble has paid off, and she has a fully functioning nest,

0:46:51 > 0:46:55ready to receive her first batch of eggs.

0:47:02 > 0:47:04Taking over a nest of field ants

0:47:04 > 0:47:07is the way typical wood ants start a new family.

0:47:09 > 0:47:12But how about the queens from a super-colony,

0:47:12 > 0:47:15with their multi-family, communal nests?

0:47:15 > 0:47:17Have they found a more peaceful strategy?

0:47:19 > 0:47:24Each mated female has to set out on her own journey.

0:47:24 > 0:47:26If she's to become a true queen,

0:47:26 > 0:47:29she has to find a nest that will accept her,

0:47:29 > 0:47:34and that is where the tolerance of the members of the super-colony

0:47:34 > 0:47:36is tested once again.

0:47:39 > 0:47:41Being already in the heart of a super-colony,

0:47:41 > 0:47:45these newly mated queens don't have to walk far

0:47:45 > 0:47:47before encountering their own kind.

0:47:51 > 0:47:54But even for a super-colony queen,

0:47:54 > 0:47:57walking straight up to a busy trail is risky.

0:47:57 > 0:48:00If the workers she meets are not in a welcoming mood,

0:48:00 > 0:48:02they will tear her to pieces.

0:48:26 > 0:48:31Slowly, one by one, workers come to investigate her.

0:48:37 > 0:48:41Some seem uncertain whether to attack or not,

0:48:41 > 0:48:43but others lick and clean her.

0:48:54 > 0:48:59After a few tense moments, a worker starts to drag her towards the nest.

0:49:02 > 0:49:05This is a sign that she will be adopted.

0:49:11 > 0:49:15And now scientists have made a further discovery.

0:49:15 > 0:49:20Many nests in the super-colony shortcut the whole process.

0:49:22 > 0:49:27The winged males and the queen ants don't even bother to leave the nest.

0:49:27 > 0:49:29Many different families live here,

0:49:29 > 0:49:33so there's no need to fly away to avoid inbreeding.

0:49:39 > 0:49:41The winged queens can simply mate

0:49:41 > 0:49:43with one of the males that hatched here.

0:49:45 > 0:49:49Perhaps this unusual behaviour is the next stage

0:49:49 > 0:49:51in the evolution of the super-colony.

0:49:59 > 0:50:01With these innovative mating systems,

0:50:01 > 0:50:06the super-colony queens don't take the same risks

0:50:06 > 0:50:08as normal wood ant queens.

0:50:08 > 0:50:11They don't need to infiltrate the nest of field ants

0:50:11 > 0:50:13to start a family.

0:50:14 > 0:50:18The workers just build new nests where needed,

0:50:18 > 0:50:22enabling the super-colony to extend deep into the forest

0:50:22 > 0:50:24where there are no field ants.

0:50:27 > 0:50:29It's changes in behaviour like this

0:50:29 > 0:50:33that most likely gave rise to the super-colony in the first place,

0:50:33 > 0:50:37and colonised this new habitat with all its riches.

0:50:42 > 0:50:45It's possible that this kind of co-operation

0:50:45 > 0:50:50between different nests is becoming more common among ants.

0:50:50 > 0:50:53New super-colonies are still being discovered

0:50:53 > 0:50:56in different species across the world.

0:50:56 > 0:50:59Are we perhaps witnessing the next stage of

0:50:59 > 0:51:01the social conquest of the Earth?

0:51:04 > 0:51:08The super-colony consists of literally thousands of

0:51:08 > 0:51:13different families, all working in co-operation.

0:51:13 > 0:51:17It's a development that mankind achieved a very long time ago,

0:51:17 > 0:51:20and could be seen as one of the reasons why

0:51:20 > 0:51:24we have come to dominate so many parts of the planet.

0:51:24 > 0:51:28Could it be that peace is the winning strategy

0:51:28 > 0:51:30on this ant mountain too?

0:51:55 > 0:51:58Much about the super-colony remains unknown,

0:51:58 > 0:52:00and for good reason.

0:52:01 > 0:52:05These ants move incredibly quickly.

0:52:05 > 0:52:10So you can see why they're so difficult to study,

0:52:10 > 0:52:12and even more difficult to film.

0:52:14 > 0:52:17At around 8mm in length,

0:52:17 > 0:52:20these are bigger than many ants but, to us,

0:52:20 > 0:52:24they're still tiny, and rarely stay still for more than an instant.

0:52:25 > 0:52:28To keep track of their frantic movements while also

0:52:28 > 0:52:30getting down to eye level with their world

0:52:30 > 0:52:32needed a very special camera...

0:52:34 > 0:52:39..the brainchild of filmmaker Martin Dohrn.

0:52:39 > 0:52:41This is Frankencam.

0:52:41 > 0:52:44It's a device for positioning tiny cameras and

0:52:44 > 0:52:47small wide-angle lenses into awkward corners

0:52:47 > 0:52:50with extreme precision.

0:52:52 > 0:52:54It's called Frankencam because

0:52:54 > 0:52:58it's got so many different bits in it.

0:52:58 > 0:53:01It has been said that it is an unholy alliance

0:53:01 > 0:53:06between other bits of equipment that should never have been put together.

0:53:06 > 0:53:08Now known by all of us as Frank...

0:53:08 > 0:53:10OK, bring Frank to me.

0:53:10 > 0:53:12..it enables us to follow tiny creatures

0:53:12 > 0:53:15as they go about their lives without disturbing them.

0:53:18 > 0:53:21I first met Frank back in 2005

0:53:21 > 0:53:25when filming for the BBC series Life In The Undergrowth.

0:53:25 > 0:53:29Back then, he wasn't quite as sophisticated as he is now,

0:53:29 > 0:53:32but he still allowed us to see ants in a new way.

0:53:33 > 0:53:3712 years on, the equipment has grown into this,

0:53:37 > 0:53:42and this enables us to enter the world of the ants

0:53:42 > 0:53:45in a way that has never been achieved before.

0:53:45 > 0:53:49Martin, there's a lot of things going on over here.

0:53:49 > 0:53:53And long cabling allows operators to take the control box

0:53:53 > 0:53:57away from the camera so that biting insects are less of a problem.

0:53:57 > 0:53:59What's going on?

0:53:59 > 0:54:02But of course, it doesn't stop the ants coming to us.

0:54:04 > 0:54:07- SHE LAUGHS - I'm covered in ants!

0:54:07 > 0:54:10I'm finding it a little hard to concentrate.

0:54:11 > 0:54:14And with Frank's fluid movements,

0:54:14 > 0:54:17keeping the action in focus is far simpler than it would be

0:54:17 > 0:54:20using a conventional close-up camera.

0:54:20 > 0:54:24It's incredibly easy to fine-focus, to go right in for the close-up

0:54:24 > 0:54:26so we can pull out for the wide shots,

0:54:26 > 0:54:29and we can see the detail, we can see the distance,

0:54:29 > 0:54:32we can put the whole scene in this meadow

0:54:32 > 0:54:34so we can see it's this meadow,

0:54:34 > 0:54:37and it makes it easier to feel as if you're there.

0:54:37 > 0:54:39And now, for the first time,

0:54:39 > 0:54:42the ants are in focus no matter where they're moving,

0:54:42 > 0:54:44and even I am too!

0:54:46 > 0:54:50However, while Frank's body parts cost many thousands,

0:54:50 > 0:54:53and its construction needed the help of a mathematician

0:54:53 > 0:54:56and an engineer, ironically,

0:54:56 > 0:54:59the lens used for many of the most spectacular images

0:54:59 > 0:55:03cost just £8 on the internet.

0:55:03 > 0:55:06This wasn't a cost-cutting measure.

0:55:06 > 0:55:10This lens has an amazing abilities, and it's perfect for the job,

0:55:10 > 0:55:12but it's only so cheap because lenses like it are made

0:55:12 > 0:55:17in their many millions for the cameras on your mobile phone.

0:55:21 > 0:55:25One of the clever ways Frank's lenses takes us into the ants' world

0:55:25 > 0:55:28is by changing the way we see distances.

0:55:28 > 0:55:32To an ant, five feet might as well be half a mile.

0:55:35 > 0:55:40VOICEOVER: This behind-the-scenes image, recorded on a normal camera,

0:55:40 > 0:55:44shows just how close I'm sitting to the nest.

0:55:44 > 0:55:47But if we view the same scene using Frankencam,

0:55:47 > 0:55:49it appears as though I'm much farther away.

0:55:49 > 0:55:52..which are emerging just now.

0:55:52 > 0:55:56It's this magnifying of distances that allows the operator to steer

0:55:56 > 0:55:59so precisely between every blade of grass

0:55:59 > 0:56:03and enables us to appreciate the world on ant scale.

0:56:06 > 0:56:09But even with Frank, there's one factor

0:56:09 > 0:56:12which affected every aspect of the ants' behaviour

0:56:12 > 0:56:14that we couldn't control.

0:56:16 > 0:56:20The weather up here is extraordinarily unpredictable.

0:56:20 > 0:56:22You never know what's going to happen.

0:56:22 > 0:56:26This morning, there was lovely sunshine. Look at it now!

0:56:26 > 0:56:29Difficult to believe, but yesterday,

0:56:29 > 0:56:32these meadows were under three inches of snow.

0:56:32 > 0:56:36So you have to be prepared for anything,

0:56:36 > 0:56:40whether you're an ant or, indeed, a naturalist!

0:56:42 > 0:56:45The ants have worked out how to survive here.

0:56:45 > 0:56:47We're novices.

0:56:47 > 0:56:49It was meant to be spring now,

0:56:49 > 0:56:52and this was meant to be the shoot we did six weeks ago.

0:56:54 > 0:56:56With the weather so variable,

0:56:56 > 0:56:59predicting the ants' behaviours was difficult.

0:56:59 > 0:57:03We've just arrived and found the nest covered in winged ants,

0:57:03 > 0:57:06which we weren't expecting at all.

0:57:06 > 0:57:09We were kind of expecting them to come out in about

0:57:09 > 0:57:11a week or two weeks' time.

0:57:11 > 0:57:13Even the scientists are pretty surprised.

0:57:13 > 0:57:18Matters aren't helped by Frank being just as fickle as the weather is.

0:57:18 > 0:57:21Unfortunately, Frank is temperamental, and sometimes,

0:57:21 > 0:57:24he's brilliant, and then as soon as you admit that he's brilliant,

0:57:24 > 0:57:26he decides to stop working,

0:57:26 > 0:57:28which is exactly what happened this morning.

0:57:28 > 0:57:31The focus box has received a knock, or it's been, you know...

0:57:31 > 0:57:34..it's decided to stop working, anyway.

0:57:34 > 0:57:36Kit failure is always a concern,

0:57:36 > 0:57:39but when there's only one of your camera in the world,

0:57:39 > 0:57:41you just need to find a way to carry on,

0:57:41 > 0:57:44and doing so enabled us to record behaviour

0:57:44 > 0:57:47scientists can't normally observe in such detail.

0:57:49 > 0:57:52Like the intricacies of antenna movements

0:57:52 > 0:57:53when ants interact.

0:57:57 > 0:58:00Or following a parasitic queen through the undergrowth

0:58:00 > 0:58:03as she slowly builds her chemical disguise.

0:58:05 > 0:58:08To obtain new observations leading to a new understanding

0:58:08 > 0:58:12of the ants, the team filmed for over 100 days,

0:58:12 > 0:58:14spread over a year.

0:58:14 > 0:58:16And the ants love it!

0:58:16 > 0:58:19Thank you. I'm happy. Great. Lovely. Thank you, guys.

0:58:19 > 0:58:22With the help of Frankencam,

0:58:22 > 0:58:26they took us into the world of the super-colony

0:58:26 > 0:58:28and, remarkably,

0:58:28 > 0:58:32using a tiny lens just like the one on the phone in your pocket.