Ants and bees have become paragons of a system that's coordinated but without central control. Intelligence does not belong to one dictating alpha but is distributed across the entire group. Two types of intelligence operate in a group: adaptive " which means decisions stem from the interplay between individuals " and collective " a group of agents acting together as a single cognitive unit.
Organisms are inherently competitive, yet cooperation is widespread. Genes cooperate in genomes, cells cooperate in tissues, and individuals cooperate in societies. Traditionally, when human societies weren't as big as they have become now, healthy, enduring social structures amongst humans were formed in small family and tribal units and lasted for centuries. In contrast, when humans have attempted to gather in nations and empires, endless troubles, power-struggles and instabilities have emerged.
For both, humans and animals, living in a group makes sense because there are many more beings to provide vigilance and defence, mating is easier, help is available, and heat is conserved better. Foraging is easier too. So is babysitting, feeding, sleeping, huddling, hibernating, and migrating.
Animals may aggregate by mutual attraction to each other, or by mutual attraction to limited resources. Bark beetles form large aggregations by mutual attraction to the bark of a fallen log and also to the odours of other members of their species.
Once animals are grouped, a mechanism comes into play that makes living in a group efficient. In some treehopper aggregations, nymphs communicate the threat of a predator by using vibrations, which humans can detect only with electronic instruments. Eastern tent caterpillars stay in a communal tent that increases in size as they grow and add silk. Colony members leave the tent on brief forays to feed on foliage and lay chemical trails for other group members to follow. In colony birds, such as cliff swallows, unsuccessful individuals often watch other birds returning to their nests with food and follow them to productive foraging sites. Pack of hyenas or wolves cooperate to bring down a zebra.
Migration in herds is common and can involve huge numbers of individuals. More than one million blue wildebeest migrate in a clockwise fashion over the plains of East Africa, covering a distance of over 2,500 kilometres each year in search of grass. The African desert locust swarms cover as much as 200 square kilometres, billions of individuals moving cohesively in search of food. The now-extinct passenger pigeon of North America, hunted to death for sport, migrated in groups of millions in search of food.
In long-term and stable social groups, interactions among members are often altruistic. For example, when a ground squirrel sounds an alarm call to warn other group members of a nearby coyote, it draws the coyote's attention and increases its own odds of being eaten. Similarly, a female meerkat forgoes reproduction and, instead, feeds the young of another group member.
Over a period of time, group living also gives rise to new behaviours. Humans are not the only ones that indulge in nepotism: apes also have preferential treatment of kin, hierarchies in societies are also developed by monkeys and chickens, and individuals form alliances within groups.
Like humans, animals form complex societies. Fish too have groups based on business opportunities. Cleaner fish are in charge of chewing off parasites from the bodies of bigger fish in coral reefs. Over the years, they have developed a distinctive blue-yellow uniform colour and stand in groups. Cleaners also have an enforceable customer service code. If they accidentally end up biting a customer, rather than cautiously nibbling off the parasites, the other cleaners punish the irresponsible worker. It's one of the only observed instances of a species punishing members in a systematic fashion.
Chimpanzees run efficient military operations. During a 10-year study research on a community of chimps in Uganda, scientists found that every so often, groups of chimp males would form up and head north, towards the border between their territory and the neighbouring tribe's land. They would stealthily move through the jungle in single-file, with practically no eating, or socialising. They would cautiously look for signs of individuals from the other tribe, such as faeces, abandoned termite-fishing tools, etc. When they found a member of the northern tribe on his own, they would kill him right away. After analysing the pattern, scientists found that the chimpanzees were at war. They were fighting over land and doing it in a very organised way. In Tanzania, researchers witnessed a civil war when one section of angry chimps split from the larger group. Over the next five years, the breakaway group destroyed the original tribe with a series of sudden and well thought out attacks.
Monkeys always seem to be grooming one another. But more than altruistic group activity, picking lice out of fur is their currency. Females trade grooming for sex, for instance. Researchers saw females would sleep with someone in exchange for eight minutes of grooming. This system obeys the law of supply and demand " when there were fewer females around, the price went up to 16 minutes of grooming for sex. Grooming isn't exchanged for only sex. Female monkeys groom other females in exchange for favours (for instance, in order to hold their infants for a specific amount of time). When scientists trained a velvet monkey to open crates containing apples for the other monkeys, soon she was the most well-groomed monkey in the group (in a community of monkeys, "rich" monkeys are distinguished by how nice their fur looks). Then they trained another monkey to do the same thing. Sure enough, the amount of grooming the first monkey got dropped in half.
Fifty million years before humans thought of growing their own food, ants were already practising the art of group sustainable agriculture. Leafcutter ants take cut up bits of plants into their ant-hills and, instead of eating them, they lay the bits down and defecate on them so that fungus starts growing. They cultivate this fungus and protect it from other, non-edible fungi " they are not only farming, but they've also made safe and effective pesticides.
Orca whales teach each other everything " from singing, eating new foods to fishing. One of the orca whales at Marine Land, Canada, evolved a brilliant bird-catching method: he would take some fish, chew them and spit them out on the surface of the water as bait. When a bird dived down for the easy meal, the whale would leap up and eat the bird. Soon, the other orcas started doing the same.
Cuttlefish live in schools. They can disguise their bodies into different patterns to accomplish different things at the same time. One half of its body may be designed to attract a mate, while the other half is a completely different design to conceal itself from predators. They employ shape-shifting strategies to conceal themselves as coral or algae. A cuttlefish has maybe ten million little colour cells in its skin. It can assess the colour and texture, of their surroundings and emulate it in seconds. They even use certain colours to assert dominance in their group.
When frightened, most humans in groups forget the welfare of others and try any means of surviving. That is what causes panic rushes during fires and being trodden over by people in a rush to escape. Sheep do the same. As sheep have limited means of defence from predators, their main defence mechanism is to instinctively flock together and flee from danger. Research has also shown that, instead of fleeing randomly when faced with danger, sheep head straight for the centre of the flock. According to a study done by Andrew King, and published in Current Biology, the strongest sheep will fight their way to the centre, which offers them greater protection.