Not all ground-dwelling ants live in direct contact with the soil. Some species, like this Polyrhachis (Campomymra) sp., line their nest cavities with wood pulp. Others may use silk or a fungal carton matrix. Yandoit, Victoria, Australia.
A nest of Pogonomyrmex badius, the Florida harvester ant. Nests of this species are characteristically ringed with debris and small pieces of charcoal, which are thought to serve as a boundary to keep other ants away from the nest entrance. Archbold Biological Station, Florida, USA
A Pseudomyrmex spinicola acacia ant pauses outside the nest entrance. The ants cut a circular entrance hole to gain access to the inside of the hollow thorn. Chiriqui, Panama.