eir dense hair which may be red, black, white, silver, or gold. They are known for their extremely painful sting, facetiously said to be strong enough to kill a cow, hence the common name cow killer or cow ant.
They invade the nests of wasps and bees as their exoskeleton is very tough and roughly textured to protect against stings. Like related families in the Vespoidea, males have wings but females are wingless. They exhibit extreme sexual dimorphism; the males and females are so different that it is almost impossible to associate the two sexes of a species unless they are captured while mating. In a few species the male is so much larger than the female that he carries her aloft while mating, a characteristic that is also seen in the closely related family Tiphiidae. In all Hymenoptera only the females sting because the stinger is a modified ovipositor. Like all wasps they can sting multiple times. A structure called a stridulitrum on the metasoma is used to produce a squeaking, chirping, or humming warning sound when handled.
Female (left) and Winged Male Velvet Ants.
Mature velvet ants feed on nectar. Although most species are strictly nocturnal, females some species are sometimes active up to two hours before sunset. It is thought they may not avoid light but rather are active during temperatures which usually occur only after sunset but on cool overcast days could occur earlier.
The male locates a female on the wing and mates. The female then enters an insect nest, typically a ground-nesting bee or wasp nest, and deposits eggs near the larvae or pupae. Her young develops as an ectoparasitoid, eventually killing and eating its immobile host. A few European species have been known to invade and raid bee or wasp nests.
Velvet ants occur worldwide, with some 5000 species, mainly in the tropics. They are especially common in desert and sandy areas, with most of the over 400 North American species found in the Southwestern United States and adjacent parts of Mexico, with others found in generally sandy regions th