These wasps live in hidden nests, which are either underground or in the wall cavities or ceilings of buildings. A mature nest is the size of a football and is constructed of a papery material. The combs are covered completely with a balloon-like envelope. Adult forms include fertile females (queens), workers (females, usually sterile), and fertile males. In late summer, colonies produce new queens and males. After mating, these new queens go into hibernation. Males and workers do not survive the winter. The following spring the queen emerges from hibernation and searches for a suitable nesting site. She then collects wood or other vegetable fiber from shallow cells. Females cooperate in nesting, exhibiting reproductive division of labor. Opens in full view