swarm logic
n. The process by which a large number of unintelligent entities can, by working together without central direction, produce intelligent action.
Ant colonies are remarkably similar to cities. No one choreographs the action, not even the queen ant, but ant behavior is controlled by swarm logic — put 10,000 dumb ants together, and they become smart. They will calculate the shortest routes to food supplies sniffing out pheromone signals from other ants and Johnson says people do the same thing in cities using low-level interactions of people on the street.
—Alex Cukan, “Stories of modern science,” United Press International, October 08, 2001
1995 (earliest)
Technology and biology are becoming one. [Kelly] pursues this notion through to the idea of 'swarm systems', collective structures like beehives and ant colonies in which the behaviour of the whole emerges from the operations of the individual elements but does not have a simple, causal and predictable relationship with them. …

Kelly convincingly argues that contemporary business practice, for example, is benefiting from the application of swarm logic to manufacturing structures and to traditional company hierarchies. Swarm logic underpins the Internet and could significantly transform our understanding and operation of television.
—John Wyver, “Lights, camera, action, e-mail?,” The Guardian, May 22, 1995
Two books — one new and the other a few years old — have released the phrase swarm logic into the lexical wilds. The newer of the two is Emergence: The Connected Lives of Ants, Brains, Cities and Software, by Steven Johnson (Scribner, 2001). The first citation is from a review of this book.

The older book is Out of Control: The New Biology of Machines, Social Systems and the Economic World, by Kevin Kelly (Perseus, 1995). The earliest citation comes from a review of Kelly's book.