Ethological studies in the ant Tetramorium caespitum Mayr. I. Foraging and building behavior.

Carrying heavy objects is a common element in the foraging and building behavior of ants. The initial stages of this behavior, i.e., lifting and moving in T. caespitum displayed as stereotyped patterns of movement. These patterns do not improve as the ants become older and more experienced, which suggest their congenital nature. Growing experience of ants is manifested in the later stages of the transportation of heavy objects, and especially in entering the correct opening of the nest with the carried prey. When a foraging ant leaves its nest to return to the prey it initially moves in the general direction of its objective. It is not until a certain distance from the nest is reached, that the ant is able to use olfactory stimuli to locate and follow its previous path. These observations indicate that the representatives of this species do not learn an exact way to and from the nest but instead have a memory for direction. The congenital character of these basic elements of foraging and building behavior allows the existence of a social organization without a division of work and foraging areas.