"It is generally not believed that any ant in an ant colony knows how the ant colony works. Each ant has certain things that it does, in coordinated association with other ants, but there is nobody minding the whole store. No ant designed the system. An important part of social biology is relating the world of the individual ant to the world of the ant colony. The colony is full of patterns and regularities and balanced proportions among different activities, with maintenance and repair and exploration and even mobilization for emergencies. But no individual ant knows whether there are too few or too many ants exploring for food or rebuilding after a thunderstorm or helping to carry in the carcass of a beetle. Each ant lives in its own little world, responding to the other ants in its immediate environment and responding to signals of which it does not know the origin. Why the system works as it does, and as effectively as it does, is a dynamic problem of social and genetic evolution. How it works -- how it is that the limited set of choices made by each ant within its own truncated little world translates, in the aggregate, into the rich and seemingly meaningful pattern of aggregate behavior by which we describe the society and the economy of the ant -- is a question akin to the question of how it is that all the cows know how much milk is needed to make the butter and the cheese and the ice cream that people will buy at a price that covers the cost of maintaining and milking the cow and getting each little piece of butter wrapped in aluminum foil with the airline's own insignia printed on it."
Thomas C. Schelling, Micromotives and Macrobehavior (1978)