Camponotus compressus, the common black ant (fig. 1), is one of the most abundant and best known species of ants in South India. The worker is a large jet-black ant ranging in length from 6 to 16 mm. with moderately large eyes, brownish legs and antennae and a prominent shining abdomen. These ants live in enormous communities, travelling long distances from their nests, and are active at all times of day and night. Though ordinarily of a peaceful disposition, when alarmed or disturbed they may display a tendency to be quarrelsome.