Formica pergandei (red) is a social parasite that kidnaps brood from other ant species to use as labor. Here, guards from a target Formica glacialis colony put up a tough enough fight that the kidnappers failed to breach the nest. South Bristol, New York, USA.
Oecophylla longinoda, the tailor ant, is fiercely territorial. Here they have pinned down a Polyrhachis intruder that has stumbled onto their tree. St. Lucia, KZN, South Africa
Minor workers of Pheidole spininodis (left) and Pheidole bergi lock mandibles in a fight between competing colonies. Jujuy, Argentina
