1. The process by which unorganized actions of individuals serve as stimuli to the actions of other individuals, and usually result in a single outcome: "Stigmergy is a mechanism of indirect coordination between agents or actions with the principle being that the trace left in the environment by an action stimulates the performance of a next action with the same or a different agent."
2. A group of individuals who collectively behave as a sole entity: "The world-wide web is considered to be human stigmergy."

Ant trails and nest building are accomplished by using stigmergy."