Army ants

Definition

Ant species characterized by aggressive, cooperative group foraging behavior in which large numbers of workers forage simultaneously across a limited area in organized raids to overwhelm prey. The term applies to multiple convergent lineages rather than a single clade, encompassing over 200 species across several subfamilies including Dorylinae (Old World) and Ecitoninae (New World). Army ants exhibit nomadic colony cycles with alternating stationary and migratory phases, and many species lack a permanent nest structure.

Etymology

From the military-like coordinated movement of foraging columns and their capacity to consume or displace most animal life in their path.

Example

Eciton burchellii, a New World army ant, forms swarm raids up to 20 meters wide that can capture thousands of prey items per day, including other arthropods, small vertebrates, and brood from neighboring ant nests.

Synonyms

• legionary ants
• Driver ants
• raiding ants

Related Terms

• swarm raiding
• column raiding
• nomadic phase
• statary phase
• Bivouac
• social predation
• myrmecophagy

Usage Notes

Not a formal taxonomic group; the term describes a behavioral syndrome that has evolved independently in multiple lineages. "Driver ants" usually refers specifically to African Dorylus species, while "legionary ants" is sometimes reserved for Neotropical Ecitoninae. The distinction between swarm-raiding and column-raiding army ants reflects different foraging geometries and prey capture strategies.