Conspecific aggression is a common problem amongst laboratory housed male mice. While C57BL/6  are not the most aggressive strain we house, they are exceedingly common, and dealing with conspecific aggression in this strain and others is a common. This session will delve into recent literature addressing home cage aggression in mice to review results from multiple strategies instituted to attempt to behaviorally manage aggression in male mice. This session will review the biology of aggression in mice, the characterization of aggression, and the effect of multiple intervention strategies, specifically the effect of weaning age and different enrichments on conspecific aggression in C57BL/6  male mice.