Larger colonies do not have more specialized workers in the ant Temnothorax albipennis

Abstract

Social insects are distinguished by their extraordinary degree of cooperation and the complexity of their group organization. However, a high proportion of individuals (often >50% at any one time) in a social insect colony tend to be inactive. It has been hypothesized that larger colonies can afford such inactivity because of efficiencies gained through stronger division of labor. We quantify the degree to which colonies of different sizes exhibit division of labor, and what proportion tends to be inactive, in the ant Temnothorax albipennis. Colony size neither influenced individual specialization nor overall division of labor in this species and larger colonies did not show a higher proportion of inactive workers. Interestingly, small colonies seemed to rely more on a small number of high-performance workers: the proportion of work performed by the single most active worker is significantly higher in smaller colonies for several tasks. More research is needed to resolve when and how colony size affects collective organization and division of labor in insect colonies.