The organization of labour in ant colonies: relations with places and objects of activities

Abstract

This paper reports the main results of a research project about the division of labour in laboratory colonies of the fungus-growing ant Atta sexdens rubropilosa. Activities performed inside and outside the colonies were cross-analyzed in terms of its distribution according to size and age classes of workers. The results show a quantitative division of labour among workers of different sizes, and suggest a division of the workers’ caste into four size-related sub-castes according to the prevailing object of their activities. As to age classes, place appears as the main factor in the distribution of activities, younger workers performing mostly internal tasks. The results of an experimental manipulation of the workers access to external areas did not affect the distribition of leaf cutting and leaf transportation among workers of different size classes. Implications of these results to the understanding of the mechanisms of labour organization in ant colonies are discussed, and directions for further experimental investigations on the topic are suggested.