Activity cycles in ant colonies: worker interactions and decentralized control

Summary

In this chapter we look at the phenomenon of periodic activity cycles in ant colonies. Although most of the information on activity cycles in ant colonies is available for Leptothorax, it seems to be a phenomenon that occurs widely. Cycles of activity that last approximately one-half hour occur in colonies, with their occurrence being a function of the number of individuals that are in an aggregate or a colony. The presence of brood has an important influence on activity cycles, increasing the degree of periodicity, though brood are neither necessary nor sufficient for the production of periodic activity. We discuss models for the production of activity cycles and divide the models into two basic groups, those that require global colonywide variables that influence each colony member and those which are based on local interactions with no global connections among workers. We find that the local models, which have explicit spatial structure, are more realistic and have greater predictive power even though they are often more cumbersome to use. Finally, we consider the functional basis for periodic activity in ant colonies. There is essentially no information about the function or possible adaptive significance of this widespread, colony-level phenomenon.