The name “velvet ant” is a misnomer. These insects are not ants but are, in fact, wasps. Males are winged, and are not frequently observed by most people. Females are wingless, ant-like in general appearance, and may be seen scurrying about on the ground. Both males and females are covered by dense, velvety pubescence, hence the name velvet ant. They are also sometimes called “cow ants” or “cow killers” (although there is nothing to indicate that any cow has ever been killed by one).
Although not as abundant in the Southeast as in the Southwest, the family is still represented in South Carolina by six different genera and 41 different species. Of these, only one is commonly seen by the general public, Dasymutilla occidentalis, the large red and black velvet ant pictured above. Most of the velvet ants belonging to the genus Dasymutilla are relatively large (1/2"-1" in length) and brightly colored. Many have brilliant patterns of black with red, yellow, or orange. The colors make these wasps distinct. This acts much like a yellow or red traffic light, giving warning of possible danger. Although the winged males are harmless, the wingless females can inflict a severe sting S one to be avoided. The sting, though extremely painful, is rarely dangerous. Velvet ants may also produce a squeaking sound when disturbed. This also acts as a warning. The sound is produced by rubbing parts of two abdominal segments across one another.
Velvet ants may be seen during the warm periods of the year. In South Carolina, they are common from about May through September. They are most commonly seen during the cooler daylight hours, especially late in the afternoon.
Information on the biology of velvet ants is incomplete. It is known that they are parasites of other predominantly ground-nesting bees and wasps. Females lay their eggs individually upon the pupae or prepupae of their host. The parasite then develops at the expense of the host, eventually killing it.
Velvet ants are rarely plentiful enough to become a nuisance. They usually remain outdoors, in sandy areas, though they may very infrequently be found in dwellings. They should never be picked up by hand, or stepped on with bare feet. Due to an extremely tough integument (outer covering), chemical and mechanical control are not very effective. Careful removal of the insect to a more desirable location is the control method of choice. Or, if they are not hurting anything (or anyone), just leave them alone.