To this family belong the potter wasps. They differ from the papermaking wasps in being solitary and in constructing their nests of mud or clay, instead of macerated woody fibre or pulp. It is perhaps one of the largest, if not the largest, families in the Vespidea, and is well represented in all parts of the world by many genera and species.The species superficially resemble the Vespidæ, but are quite distinct and are easily distinguished by the cleft or toothed claws, the claws never being simple or edentate as in the social wasps.The family, like the Vespidæ, has reached its greatest development in warm or tropical countries.