Summary: The velvet ant is actually a wasp that closely resembles an ant. They are covered in hair that is often brightly colored, which serves as a warning to predators that this wasp can deliver a painful sting.
The velvet ant, also known as Cow Killer, is one of the tougher creatures in the insect world. The velvet ant, which is actually a type of wasp, has a very hard exoskeleton, and the hairs on its body also serve as protection from other wasps and bees. The velvet ant is an invader, so its defenses are necessary for its survival.
The velvet ant female is wingless. She lays her eggs into the nests of ground dwelling bees and wasps so that the larva of the velvet ant has a food source when it hatches from its egg. The velvet ant larvae feed on the larvae in the bee or wasp nest, and the velvet ant larvae will kill the larvae of the bee or wasp, thus making the velvet ant larvae parasitoids.
Velvet ants are closely related to actually ants, but there are a few differences. First, velvet ants do not have bent antennae. Also, the œwaist of velvet ants, or the area between the thorax and abdomen, does not narrow dramatically like an ant's body. Velvet ants are about an inch long, but there is great variation among the 5,000 or so species. Males are often much larger than females, which is unusual for insects. Males have black, translucent wings, while females are wingless.
Adult velvet ants feed on flower nectar. They live all around the world, but are more common in desert or sandy environments where ground dwelling bees and wasps are often found. Most of the velvet ants are nocturnal, avoiding the heat of the sun, but a few walk about during the day. Velvet ants live most of their life in solitude. When mating season occurs the male ants will fly low to the ground in search of a female. After mating the female uses her ovipositor to lay her eggs into the nest of a bee or wasp. This is when the female's stinger and thick coat of hair and hard exoskeleton come in handy as protection from the bees and wasps that are angry at the parasitic invader.
You should avoid handling velvet ants because they have a very painful sting. They got the name cow killer because the sting is so painful that it can kill a cow. Actually, that isn't true, and the name might have developed because a sting could lead to infection by bacteria or sawflies that could eventually kill a cow, but the description of how painful their sting is, is how the name cow killer got stuck. Velvet ants are not aggressive and will try to escape rather than defend territory if you approach them. However, if you pick them up they can squeak loudly and deliver a venomous sting.
There are no pesticides designed specifically for velvet ants due to their uncommonness and solitary nature. If you find an infestation of velvet ants you can try to eliminate the nests of ground bees or wasps that are attractive breeding sites for velvet ants. Try reducing sandy patches where ground bees or wasps inhabit. You might do this by planting grass over the area.