An individual ant barely has a brain, yet colonies of them dominate their world. When ants swarm over a pile of food and carry it back to their nest, piece by piece, they look like a disciplined army, marching in lock step. But the army has no general, no boss ant telling the troops where to go. No one is giving orders. It's a marvel that has long entranced scientists, and now some are adapting ant tricks to human problems, from dispatching gasoline trucks to managing traffic on the Internet.
Ants use chemical clues and simple behaviors to accomplish their goals.
If an ant wandering aimlessly finds some food, it will grab a piece and head back to the nest. Other ants smelling the trail will follow it to find the food. Ants are dumb, so some will, by accident, take a long route home. But pheromones build up more quickly on a shorter route, researchers have found, which is why ant colonies tend to settle quickly on the most efficient path between food and nest. No one has to issue any orders.