The Mutillidae are a family of more than 3,000 species of wasps whose wingless females resemble large, hairy ants. Their common name velvet ant refers to their dense pile of hair, which most often is bright scarlet or orange, but may also be black, white, silver, or gold. Black and white specimens are sometimes known as panda ants due to their hair coloration resembling that of the giant panda. They are known for their extremely painful stings, hence the common name cow killer or cow ant. However, mutillids are not aggressive and sting only in defense. Only female mutillids are capable of inflicting a sting. In addition, the actual toxicity of their venom is much lower than that of honey bees or harvester ants. Unlike true ants, they are solitary, and lack complex social systems.