The Cow Killer Ant is also known as Velvet Ant or Red Wasp. While called "ant," it is actually a wingless female wasp that can inflict a painful sting. The male wasp does have the advantage of flight. Some older folks will tell you that this brightly colored ant runs quickly over the ground and those who ran barefoot through fields and meadows, and who have been stung, are quite willing to fill you in on the details. So painful is their sting it is said to "kill a cow." They do not kill cows.
The body size of flightless wasps vary from ¼ inch to 1 inch in length. Most of these wasps are brightly colored (red, yellow, orange) with varying patterns. Although the male wasp has wings, the wingless female is the one most often seen. Seeing this large, wingless wasp scurry about makes most people think that they are seeing a gigantic ant. Adult flightless wasps feed on nectar, water or the larvae of other insects. Female wasps of this family lay their eggs in the larva or cocoon of a host insect. Their food can include flies, beetles, bees and other wasps.
The most frequently encountered are not generally considered as pests. They do occasionally invade residences in large numbers. But when left alone no harm is done. Be aware that if a child (or adult) tries to play with this insect or accidentally steps on it, the resulting sting will remind the offending human how it got its name. The sting of the flightless wasp can be severe enough to make someone think that it could kill a cow! Hence, the name "Cow Killer Ant" came to be.
Female Flightless Wasp, Dasymutilla occidentalis
Photo courtesy Jason Wilcox, McDavid, Florida
Male Flightless Wasp, Sphaeropthalma pensylvanica, 5-17-08