How do ant colonies organize without a leader?

The answer

Ant colonies operate through a decentralized system called stigmergy, where individual ants follow simple chemical rules based on pheromone trails rather than taking instructions from a leader. The queen's sole role is reproduction; she does not direct colony activities. Each ant responds to local chemical signals: if many ants mark a food trail with pheromones, more ants follow it, creating a self-reinforcing feedback loop. This emergent intelligence allows colonies of millions to build elaborate structures, wage wars, farm fungus, and allocate labor efficiently, all without any centralized planning.