We don't usually think of spiders as social. In fact, most are not. Even mating can be a dicey proposition. However, a degree of sociality has evolved in some spiders, including the local huntsman (Delena cancerides), which lives in family groups. The Delena genus is particularly interesting for the study of spider sociality, because both evolved and been lost in the same genus.. This project will aim to understand what makes spiders social, particularly focusing on the hypothesis that aggression is mediated by metabolic rate, in other words, pro-social behaviour can evolve by selection on metabolism. The project will use comparative physiology, gene expression and possibly population genetics to test this hypothesis.