The Mutillidae are known as Velvet Ants but also as Cow killers. The females are wingless, making them superficially resembling ants; their hairyness explains why they are called Velvet Ants. Their very painful stings explains the other vernacular name. The larva are parasitoids of a wide range of hosts, including various bees, spider wasps and digger wasps.

Source: Gauld, I. & B. Bolton, eds. 1988. The Hymenoptera, p. 233 - 234.