Dump Chambers Rather than removing waste materials, such as exhausted plant material, dead fungus and dead ants from the nest, the leaf-cutter ants store them in specially excavated dump chambers.

It is unclear why the ants do this, but it may be to prevent any parasites and diseases that may have caused the ants or fungus to die, or which have been brought into the nest on plant material, from spreading to the rest of the colony. In natural nests of some Atta species such as Atta vollenweideri and Atta cephalotes, these dump chambers are deep underground, often more than 2 m below the surface. The picture to the right shows one of the dump chambers used by a colony of Atta cephalotes in the laboratory. Atta columbica colonies, however, dump waste material on a single mound some distance outside the nest.