Small ants develop through complete metamorphosis, passing through a larval state equivalent to the caterpillar of other insects and through a pupal state. The larva has no legs and is fed by workers through a process called trophaxia, in which the worker regurgitates food that she ingests and digests. Adults also distribute food among themselves through this process.
Ants communicate via pheromones and these message signals are more developed in the ant species than in other groups of hymenopterans. When a worker finds food she leaves a trail on the way back to the colony, and that is followed by other ants that reinforce the trail when they return to the colony.When the food is finished, the trails are not marked by the returning ants and the smell dissipates.
Like other insects, ants smell with long, thin antennae. The antennas have elbows connected to the first elongated segment; and since they come in pairs-like binocular vision or stereophonic equipment they get information about direction and intensity. When two ants meet, they touch the antennae and the pheromones that are present provide information about the feeding status of each one, which can lead to trophaxia, that is, one of them regurgitates the food to the other. The queen produces a special pheromone that tells workers when to start raising new queens.
Ants attack and defend themselves by biting or stinging, sometimes injecting chemical compounds into the attacked animal, in particular formic acid.