“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.“ – David Attenborough
David Attenborough is in the Swiss Jura Mountains to discover the secrets of a giant. Beneath his feet lies a vast network of tunnels and chambers, home to a huge empire of ants. It is believed to be one of the largest animal societies in the world, where over a billion ants from rival colonies live in peace. Their harmonious existence breaks many of the rules for both ants and evolution, and raises some important questions. Through winter, spring and into summer, David turns detective to find the answers.
empire that’s about to stir [Music] the dura 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 [Music] but evidence of its existence these strange mounds is everywhere [Music] 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 managed 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 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 neighbors 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 [Music] spring is on the way 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 are recharging their batteries absorbing heat directly from the sun’s rays [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 [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 [Music] and there’s another shining wonderfully in the sunshine a normal wooden 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 [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 those unwinning 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 [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 [Music] it’s now early april the queen’s 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 using infrared 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 [Music] 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 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 [Music] spring is now well on the way the snow has disappeared and color comes to the meadows [Music] by late april there are piles of eggs in the nest and the first larvae are hatching [Music] 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 juror 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 colonies 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 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 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 assembled [Music] this is war and the weapons being used the 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 opponent’s limbs [Music] it could take seven amps 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 [Music] 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 arrests or are they surveying progress to see where help is needed [Music] 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 [Music] the victors will certainly have enlarged their territory but some say they have also gained other rewards [Music] they’re taking off the bodies of their victims and carrying them back to the nest over there to feast upon them [Music] 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 [Music] at first the resident ant makes an aggressive gesture [Music] but then the other strokes the first’s antennae that gesture is a request for food and the other obligingly feeds her [Music] 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 [Music] they do this because they share the super colony scent a chemical signature that is transferred together with the food [Music] 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 [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 [Music] it comes from the spruce trees [Music] 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 trees 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 juror the spruce trees themselves also produce a substance that the ants can use directly [Music] these ants have connected 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 [Music] the ants have a remarkable solution to that problem [Music] 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 [Music] 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 [Music] 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 [Music] the juror 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 [Music] 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 [Music] 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 the lush green hills and mountains of the juror 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 ant’s 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 [Music] she’s carrying a little sack full of eggs [Music] [Music] she decides to run for it and her sudden movement alerts the hunters [Music] that first fleeting touch by an ant left a faint scent mark and now fellow hunters can home in on their target [Music] 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 anant manages to grab her [Music] like a pride of lions taking down the buffalo the ants surround her two restrain their catch while another delivers the fresh dissolving acid the wolf spider is just one of many [Music] 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 lava is changing into an adult their time in the sun is approaching [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 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 [Music] as mid-summer approaches the jura briefly becomes a paradise of wild flowers and something new appears inside each of the nests wings [Music] 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 [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 [Music] many test their wings before takeoff they may need several attempts before they achieved complete flight control [Music] over a few days half a million wing dance of both sexes take to the air and head off for new [Music] territory they then all assemble here in the heart of the super colony [Music] 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 [Music] detecting this scent on the wind the males home in on the females [Music] 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 those males fortunate enough to couple quickly make the most of their few remaining hours of life [Music] once they’ve mated their service to the colony is over and they die of exhaustion [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 trying to remove a backpack with your feet even if you have six of them is clearly a frustrating process [Music] 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 [Music] 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 [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 making 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 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 [Music] 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 [Music] gradually her disguise becomes more and more convincing the entrance to the field ants nest is unguarded [Music] cautiously she enters [Music] inside she is vastly outnumbered wood and behavior inside the field and 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 [Music] 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 and queen has now acquired the colonies scent she oozes queenly pheromones and the field ants seem entranced by their new foreign queen [Music] 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 continental 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 [Music] after a few tense moments a worker starts to drag her towards the nest this is a sign that she will be adopted [Music] 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 [Music] 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 [Music] with these innovative mating systems the super colony queens don’t take the same risks as normal wood and queens they don’t need to infiltrate the nest of field ants to start a family [Music] 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 colonize its new habitat with all its riches [Music] 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 [Music] much about the super colony remains unknown and for good reason these ants move incredibly quickly so you can see why is there so difficult to study and even more difficult to film at around eight millimeters in length these are bigger than many ants but to us they’re still tiny and rarely stay still for more than an instant to keep track of their frantic movements while also getting down to eye level with their world needed a very special camera the brainchild of filmmaker martin dawn this is frankencam it’s a device for positioning tiny cameras and small wide angle lenses into awkward corners with extreme precision it’s called fracking cam because it’s got so many different bits in it it has been said that it is an unholy alliance between other bits of equipment that should never have been put together now known by all of us as frank okay bring it back to me it enables us to follow tiny creatures as they go about their lives without disturbing them [Music] i first met frank back in 2005 when filming for the bbc series life in the undergrowth back then he wasn’t quite as sophisticated as he is now but he still allowed us to see ants in a new way 12 years on the equipment has grown into this and this enables us to enter the world of the ants in a way that has never been achieved before there’s a lot a lot of things going on over here and long cabling allows operators to take the control box away from the camera so that biting insects are less of a problem what’s going on but of course he doesn’t stop the ants coming to us i’m covered in ants so i’m finding a little hard to concentrate [Music] and with frank’s fluid movements keeping the action in focus is far simpler than it would be using a conventional close-up camera it’s incredibly easy to find focus to go right in for the close-up so we can pull out for the wide shots and we can see the detail we can see the distance we can put the whole scene in this meadow so we can see it’s this meadow and it makes it easier to feel as if you’re there and now for the first time the ants are in focus no matter where they’re moving and even i am too however while frank’s body parts cost many thousands and its construction needed the help of a mathematician and an engineer ironically the lens used for many of the most spectacular images cost just eight pounds on the internet this wasn’t a cost-cutting measure this lens has amazing abilities and it’s perfect for the job but it’s only so cheap because lenses like it are made in their many millions for the cameras on your mobile phone one of the clever ways frank’s lenses takes us into the ants world is by changing the way we see distances to an ant five feet might as well be half a mile [Music] this behind the scenes image recorded on a normal camera shows just how close i’m sitting to the nest but if we view the same scene using frankencam it appears as i’m much farther away is this magnifying of distances that allows the operator to steer so precisely between every blade of grass and enables us to appreciate the world on ant’s scale [Music] but even with frank there’s one factor which affected every aspect of the ants behavior that we couldn’t control the weather up here is extraordinarily unpredictable you never know what’s going to happen this morning it was a lovely sunshine look at it now difficult to believe but yesterday these meadows were under three inches of snow so you have to be prepared for anything whether you’re an ant or indeed a naturalist the ants have worked out how to survive here we’re novices it was meant to be spring now and this was meant to be the shoot we did six weeks ago with the weather so variable predicting the ants behaviors was difficult we’ve just arrived and found the nests covered in winged ants which we weren’t expecting at all we were kind of expecting them to come out in about a week or two weeks time even the scientists are pretty surprised matters aren’t helped by frank being just as fickle as the weather is unfortunately frank is temperamental and sometimes he’s brilliant and then as soon as you admit that he’s brilliant he decides to stop working which is exactly what happened this morning the focus box has received a knock or it’s been you know decided to stop working anywhere kit’s failure is always a concern but when there’s only one of your camera in the world you just need to find a way to carry on and doing so enabled us to record behavior scientists can’t normally observe in such detail like the intricacies of antenna movements when ants interact or following a parasitic queen through the undergrowth as she slowly builds her chemical disguise to obtain new observations leading to a new understanding of the ants the team filmed for over 100 days spread over a year and the ants love it thank you i’m happy great lovely thanks guys with the help of frankencam they took us into the world of the super colony and remarkably using a tiny lens just like the one on the phone in your pocket