These are solitary wasp species, with nests constructed and provisioned by individual mated females. Eggs of mud daubers are laid singly on hosts in cells in mud nests provisioned with food, sealed and abandoned. Larvae grow up to 1 inch long and are cream-colored, legless and maggot-like. They pupate in cocoons within the cells and overwinter in nests. There can be several generations annually. Habitat, Food Source(s), Damage: Mud daubers (Sphecidae) build small nests of mud under overhangs like eaves of buildings. . The iridescent blue mud dauber, Chalybion californicum (Saussure), takes over nests of the black and yellow mud dauber. It provisions its nest mostly with black widow spiders.