‘Lazy’ in nature: ant colony time budgets show high ‘inactivity’ in the field as well as in the lab

Abstract

Social insect colonies are models for complex systems with sophisticated, efficient, and robust allocation of workers to necessary tasks. Despite this, it is commonly reported that many workers appear inactive. Could this be an artifact resulting from the simplified laboratory conditions in most studies? Here, we test whether the time allocated to different behavioral states differs between field and laboratory colonies of Temnothorax rugatulus ants. Our results show no difference in colony time budgets between laboratory and field observations for any of the observed behaviors, including ‘inactivity’. This suggests that, on the timescale of a few months, laboratory conditions do not impact task allocation at the colony level. We thus provide support for a previously untested assumption of laboratory studies on division of labor in ants. High levels of inactivity, common in social insects, thus appear to not be a laboratory artifact, but rather a naturally occurring trait.