Mutillidae is a family of more than 7,000 species of wasps whose wingless females resemble large, hairy ants. Velvet ants can be found worldwide. Over 400 species occur in the North American Southwest, where this male specimen was collected.

Males fly in search of females; after mating, the female enters a host insect nest, typically a ground-nesting bee or wasp burrow, and deposits one egg near each larva or pupa. The mutillid larvae then develop as idiobiont ectoparasitoids, eventually killing their immobile larval/pupal hosts within a week or two.

The exoskeleton of the velvet ant is remarkably strong. It requires 11 times more force to crush than that of the honeybee.