http://www.iflscience.com/plants-and-animals/ants-designate-space-their-nest-tiny-toilets Interestingly, the ants working in the sanitation department don't remove the poop as they do with other waste (other dead ants, etc). This behavior is still a mystery for now. http://www.iflscience.com/plants-and-animals/ants-designate-space-their-nest-tiny-toilets