Many of the collective activities performed by social insects result in the formation of complex spatio–temporal patterns. Without centralized control, workers are able to work together and collectively tackle tasks far beyond the abilities of any one individual. The resulting patterns produced by a colony are not explicitly coded at the individual level, but rather emerge from nonlinear interactions between individuals or between individuals and their environment. We present a few selected examples to illustrate some of the basic mechanisms used by social insects, such as templates, stigmergy and self–organization. These mechanisms can be used in combination to organize pattern formation at the colony level.