These solitary wasps get their common name from the very hairy females which are wingless often brightly colored and look very fuzzy. However they pack a very potent sting which has earned them the nickname of cow-killer and mule-killer. Various species are found throughout the United States.
Adults about 1/8″-1″ (3-23 mm) long. Color black with areas of often very bright red orange yellow or white. Females wingless ant-like but lack node on pedicel densely covered with hairlike setae giving a fuzzy or velvet appearance and with a long smooth stinger. Males winged wasp-like hairiness usually much reduced coloring usually dull and different from females and lack a stinger.
Females are typically seen running somewhat erratically on the ground especially on bare or sandy areas such areas are favored by many ground-nesting bees and wasps. They will occasionally enter structures for insect prey observed in second-floor bathroom feeding on springtails (Collembola) by the senior author. Males of some species are often found on flowers whereas other are nocturnal.