Potter wasp (by Natasha Mhatre on Flickr)

Potter wasps (or mason wasps) are a cosmopolitan wasp group presently treated as a subfamily of Vespidae, but sometimes recognized in the past as a separate family, Eumenidae.
The name “potter wasp” derives from the shape of the mud nests built by species of Eumenes and similar genera. It is believed that Native Americans based their pottery designs upon the form of local potter wasp nests. [von Frisch, 1974].

All known eumenine species are predators, most of them solitary mass provisioners, though some isolated species show primitive states of social behaviour and progressive provisioning.

When a cell is completed, the adult wasp typically collects beetle larvae, spiders or caterpillars and, paralyzing them, places them in the cell to serve as food for a single wasp larva. As a normal rule, the adult wasp lays a single egg in the empty cell before provisioning it. Some species lay the egg in the opening of the cell, suspended from a thread of dried fluid. When the wasp larva hatches, it drops and start to feed upon the supplied prey for a period of time that normally last some few weeks before pupating. The complete life cycle may last from a few weeks to more than a year from the egg until the adult emerges. Adult potter wasps feed on floral nectar.
Read more: Wikipedia