Raiding and Other Outstanding Phenomena in the Behavior of Army Ants

Abstract

Army ants (Eciton s. str) are characterized by their raiding, by the formation of temporary colony clusters or "bivouacs," and by periodic movements of the entire colony. The raiding activities of E. hamatum, the type species, and of E. burchelli, are described; the former representing the "column raiders," the latter the "swarm raiders." There are evident differences in the form of raiding of these two arbitrary groups, but fundamental similarities also exist. In the species studied, colony movement is a phenomenon which develops from the raiding of a given day. Whether a given colony bivouacs in one place over a period of days, or moves to a new site at the end of each day''s raiding, is definitely dependent upon the condition of the brood.