## ABSTRACT

Even though it is tempting to consider a social insect colony as a unit that collectively decides about, for instance, the selection of a given food source, a colony’s foraging response ultimately arises from the decisions made by each individual worker, and from their integration at the colony level. Individual foragers are expected to behave in a way that maximizes food intake at the colony level, because one can assume that the foraging performance of a colony, measured as the delivery rate of food, correlates with colony tness.