Why "Stigmergic"?Stigmergic communication happens in insects
through the alteration of their environment. Some specific modification
of the environment triggers some
behaviour. For instance, starting the building of a nest induces other
insects to complete it. The simle sight of an initiated nest is a
stimulus to further work.
Typically stigmergic behaviour is a form
of collaborative communication between members of a community. In the
case of SPAM, it is used against opportunistic behaviour: the simple
presence of an email address triggers unconditionate mass mailing, but
in this way it can be detected.
On stigmergy, see: Wilson, E.O. Sociobiology: The New Synthesis. (Harvard University Press: 1975). Wilson prefers to call it sematectonic communication.