This family is restricted to the paper-making wasps, all social species living in large communities and having three distinct sexes, female, worker and male, thus agreeing with the social bees, the Apidæ and Bombidæ, and with many ants, Dorylidæ, Myrmicidæ, Formicidæ, etc.

In some species, too, like the ants, there appear to be two forms of the worker.

Deceived by their habits, for structurally they are widely separated, Westwood and Packard thought the social wasps were allied to the Apidæ, and in their scheme of classification have placed them next to the bees, with which they having nothing in common.