An ant colony operates without central control. No ant can assess what needs to be done. Each ant responds to its interactions with other ants nearby. In the aggregate, these stochastic, dynamical networks of interaction regulate colony behavior. Ants are extremely diverse, and species differences in collective behavior reflect relations with diverse environments.

A long-term study of desert seed-eating ants shows that colonies regulate foraging activity according to food availability and current humidity. Colonies differ in how they regulate foraging behavior. Matching parent and offspring colonies made it possible to estimate a life table for this population of colonies and to ask how collective behavior is evolving in current drought conditions. It appears that colonies that regulate foraging so as to conserve water are having more offspring colonies.

Studies of other species, such as tropical arboreal ants in Mexico, and the invasive Argentine ant in northern California, suggest how different collective algorithms evolve in other environmental conditions.