"Working as a group is a weapon." "Prey in vast numbers can fault an attacker." "But armies can devastate where one alone would fail." "Success lies in launching a mass attack." "One thousand kilos of muscle complete with horns." "Bison are the most powerful animals in North America." "They can be deadly even to the most aggressive predators." "A wolf prowls the fringes of the herd." "It walks purposefully locked on to its prey." "The bison recognize these signs and know they must be on their guard." "But a wolf weighs only 40 kilos, the same as a domestic dog." "What could these heavy weights have to fear?" "To have any chance of success, a wolf needs two things:" "to work in a team and to select the right victim." "If it makes the wrong choice, it could end up losing its own life instead." "So the wolf must search out weakness, injury, old age or youth" "While the herd is stationary, more vulnerable members can hide behind strong bodies." "The wolves can only bide their time." "At this stage to get any closer would be dangerous." "Somehow, the wolf pack must separate the weak from the strong" "And that means getting these lumbering giants on the move." "Slowly, but surely, they harass the bison into a tighter group." "Nerves become frayed." "The strong have no problem keeping the tormentors at bay." "they are in no danger." "But the weak are no match, they panic exactly what the wolves have been waiting for." "They rush to catch up." "These are the critical moments of the hunt." "To stand any chance of success, they can't let the bison get too far ahead." "Although they look heavy and slow, a bison's top speed is 35 miles an hour." "They can sustain this pace for miles." "Wolves try to get the herd to break ranks, but they still can't get too close." "Most wolf chases last only a few minutes and they cover less than half a mile." "They quickly weigh up every individual." "If they don't find a suitable victim by then, they usually give up and conserve their energy." "This time a calf has strayed too close to the edge of the herd." "The combined attack is ferocious and the kill seems swift and certain." "But the calf is not alone." "Instinct makes adult respond to its distress whatever the risk to themselves." "The youngster seems to have cheated death, but if it's badly injured, the pack may well return later to claim it." "And a peculiar twist of fate, however, one of the rescuers itself is in trouble." "Too old, ill or slow to keep up with the herd, the wolves are quick to take advantage." "This time, there is no help available." "Unlike calves, adult bison are often left to fend for themselves." "Wolves are experts at picking at those weaker than themselves" "A scientific studies have shown they hardly ever tackle prey in their prime." "But any large animal could be dangerous to a single hunter." "That's why, for wolves, a mass attack is the answer." "The same principle applies to mass defense." "Even small creatures can fight off intruders if they stick together." "In Europe, the honeybee has evolved an apparently impenetrable defense force" "Under attack, they swarm aggressively around the entrance to their hive." "But each bee acts alone to sting any intruder, a European strategy against European predators." "The bees are protecting their future." "Inside the hive are row upon row of helpless grubs." "These are their siblings, the next generation of bees, and the adults are prepared to die to save them." "But this hive is in Japan." "The European bee has been introduced into Japan because they make twice as much honey as the native bees." "But here there is a different predator, one the European bees are powerless against." "These bags of fluid with jaws are the predator's larvae" "Five centimeters long, each one is an eating machine." "They eat meat and honey bee grubs are the ideal meal." "The larvae get their food by sending out a raiding party." "Warriors three times the size and 20 times the weight of a bee, go in search of a hive." "European defense tactics will be tested to destruction." "The aerial attack comes from giant hornets - the largest in the world." "Five centimeters long, the hornets strike with such speed they can slash and decapitate up to 30 bees in one minute." "By obeying the European instincts and defending one at a time, the bees are doing no more than queuing up to be slaughtered." "To get the grubs inside the hive, the warriors have to destroy every adult bee." "It will take three hours to kill all 30,000." "the hornets will then carry off the defenseless grubs." "The next generation of bees will feed the next generation of hornets" "Never satisfied for long, the hungry larvae strike their jaws against the side of the nest" "Their relentless demands drive the adults to raid again and again." "Scouts are sent out to locate further hives." "This one is a home to a colony of Japanese bees, a very different foe to the Europeans." "The sound of a hornet approaching sets off an extraordinary chain of events" "First, all the bees retreated to the hive to mass together." "If the hornet detects grubs, it will mark the outside of the hive with scent and return later with reinforcements." "The bees cannot afford to let this happen." "The vibrate their wings in warning." "The hornet is not deterred, but Japanese bees, unlike Europeans work together in a unique way." "They mobilize a remarkable mass attack." "Suddenly a few bees jump onto the hornet, others move in to engulf it in a dense ball." "The bees don't use their sting." "With the aid of a thermal camera, it's possible to see what's happening in this scrum." "The bees' vibrate muscles inside their bodies, so that the center of the ball gets hotter and hotter." "When it reaches 45 degrees centigrade, the hornet will die." "Bees, however, survive up to 48 degrees, just three degrees more." "The tiny, but crucial advantage of acting en masse." "It takes 15 minutes to kill the hornet messenger and save the hive." "In the central American rainforest, being outnumbered takes on a whole new meaning." "An army a quarter of a million strong is advancing." "Fear and expectation fills the air." "It will slaughter anything in its path, tearing prey limb from limb with ruthless efficiency." "This army has no general and its troops are virtually sightless." "But they have a basic instinct to kill up to 20,000 times a day." "Reinforcements constantly move to the front line while victim's body parts are ferried back to base." "This huge encampment or bivouac in the base of the tree is more than five feet tall, one of the biggest ever seen." "It is the barrack for more than a million army ants." "Although it's the blind leading the blind this awesome army is actually a model of organization and discipline." "By obeying the same simple rules, and massing together, these individuals create a super predator." "Each ant is programmed to kill anything it can and to carry the food back to camp." "To do so, it has to smell its way." "As each ant leave the bivouac it deposits a trail of scent with its abdomen." "Those behind pick up the smell with their antennae." "They track the strongest smell down to ground and across the forest floor." "A continuous stream of ants pours out from the camp guided by the even more powerful scent trails." "The front line surges at up to 12 meters per hour." "Ahead those that can make a run for it." "The army has camp followers too." "Ant birds pick off fleeing prey, but never attack the ants themselves." "Unlike the birds, the ants can't actually see their victims." "They literally bump into them as they try to escape." "When they find prey, they quickly overwhelm it, biting and stinging." "Their combined scent attracts more than 100 ants a minute." "Its death by a thousand cuts." "Taking spoils back to the camp the ants leave the same scent but a stronger trail." "Outgoing ants follow this concentrated path to the source of food." "As prey is captured all around, some trails become reinforced and others peter out." "The result is a tree of pathways that spreads out into the forest." "Each day the raiders branch out into a new direction." "About 123 degrees from the previous attack laying waste to many thousands of square meters." "Every three weeks they break camp and march through the devastation to a new part of the forest to prepare for their next mass attack." "If you are small and vulnerable, massing together makes a lot of sense." "Birds and fish swarm in graceful ballets with a cast of many thousands not just a spectacular show." "This is where huge numbers confuse and daze a predator." "Each individual seems to dance to an overall design but there is no lead and no choreographer." "Just like the army ants, their coordination is based on a few simple rules" "Only now is science bringing together technology and natural history to explain how it works." "A 3-D computer simulation shows how a mass stays together by obeying just three simple rules." "Each individual is programmed to only be aware of its nearest neighbors." "All the individuals are aligned" "And they're attracted to each other, but keep a small distance away." "Shoals and flocks form in the screen when these three basic principles are applied" "In nature, fish shoal close together about a body length or less apart" "Birds leave 3 or 4 body length between them but the models for both are exactly the same" "But this gentle drifting changes dramatically when a predator enters the scene" "Now things look much more elaborate but in fact, these are just the same basic rules" "With one obvious addition, when a predator attacks, get out of the way" "On the model, we can see the point of impact where the predator enters the group" "Just here, the rules are broken and individuals scatter away from danger" "But as soon as the predator moves past, the rule of attraction brings them back together again" "This constant splitting and reforming looks like the group thinks as one" "But in fact, it is no more than a collection of individuals acting selfishly to protect themselves" "Because the individuals of the point of attack scatter away from danger the resulting patterns are always different" "So on a computer screen and nature, we see many beautiful variations" "But the beauty has a point" "As a peregrine dives through a group of starlings, shockwave spread out" "See again, the flock's being attacked from both sides" "The waves of panic are quickly transmitted to birds half a kilometer away" "And once the current danger has passed, there are many good reasons to stay with the crowd" "An attacker is confused by the sheer weight of numbers" "There are many eyes to spot danger coming" "And the chances of being the unlucky one are much lower than in small groups" "Flocking and shoaling normally means that all of the prey survive" "But if the predator is big enough, this can work the other way" "There is one predator that has learned to encourage its prey to mass together" "These herring are now in a shoal they are relaxed and calm, feeding on plankton" "The sound of approaching danger spreads through the water" "The fish know they are in trouble and dive deeper to get out of the way" "But they are swimming straight into a trap" "Because humpback whales have a method of fishing as precise as any military maneuver" "One whale dives to find the shoal around 35 meters down" "It suckles the herring, flashing its wide fin to herd them into a even tighter ball but it's hard to control the panicky fish alone" "Other group members arrive to help and the job becomes much easier" "The whales deploy their next tactic" "Seen from below, the first whale underneath the shoal emits an incredibly loud noise" "The call as loud as a jet engine, 180 decibels" "To fish, with their acute senses, this must be unbearable" "Frantic and terrified, the fish are driven upwards at around half a meter a second" "On the surface, bubbles appear marking the next phase of this mass synchronized attack" "17m below, a single whale blows out a stream of air turning in a clockwise circle that creates a curtain of bubbles" "The humpbacks force the fish against the enclosing wall increasing their speed to three meters a second" "By the time they reach 5 m below the surface the fish are trapped within the bubble prison" "There is no way out" "Now the whales join forces for the kill" "Air explodes from their blowholes propelling the fish to the ocean surface" "This is the ultimate mass attack" "By working together, humpbacks can wipe out thousands of prey in one go" "But how do they know how to do it?" "In the next programme, we'll look at how predators learn to kill" "Some predators use intelligence to track their prey" "Green herons discover how to be master fishermen" "All formed with the killer instinct" "Some take a lifetime perfecting it" "Chimps ambush with military precision" "But what does it take to learn to become an ultimate predator" "Predators, uncovering the moments where life hangs in the balance" "Subtitles by Andrew and Hattie"