Frequent nest relocation occurs in many social insects, but the causes of this relocation behavior are not well described. In the rainforests of Central America, the colonies of the ant Aphaenogaster araneoides relocate their nests quite frequently – about once per week. Building upon earlier research, I tested the hypothesis that relocation decisions are mediated by colony odors. By manipulating the odors of recently vacated nests, I found that colonies avoid occupying nests containing the odors of colony members relative to control nests not subjected to colony member odors. I suggest that the reduction of colony odor is an important component of antipredator behavior.