These insects are not ants but are actually wasps. They get their names from the hairs that cover their body and because they resemble ants. California has about 100 species of Mutillidae that live in the desert. The Multillidae 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 can be scarlet or orange, but may also be black, white, silver, or gold in color. Their bright colors serve as aposematic signals—to warn off predators.
Velvet ants are found worldwide. Some, like the red velvet ant, are mainly found throughout the U.S., but especially in dry regions. They gravitate towards open areas like fields, meadows, and even lawns. However, because velvet ants are parasitic, they will appear wherever their host species, such as bumblebees and wasps, live. Adult velvet ants consume nectar and water from flowers. They may also consume larvae and adult insects, such as flies, bees, wasps, and beetles.
Velvet ants range in size from 1/8-inch to one inch and they feed on nectar. Their exoskeleton is unusually tough (to the point that some entomologists have reported difficulty piercing them with steel pins when attempting to mount them for displays). The males have wings but no stingers. The females have stingers but lack wings. The female is known for her extremely painful stings that can last up to 30 minutes, however, they are not aggressive and sting only in defense. The toxicity of the sting venom is much lower than that of honey bees or harvester ants. Unlike true ants, they are solitary and lack complex social systems. Both themale and female can make a squeaking sound by rubbing one abdominal segment against another.
Females are most often found scurrying along the ground looking for nests of host species, while males are found on flowers. The males will fly low to the ground seeking the females. After mating the females will look for ground nesting wasp or bee with pupal chambers (when these insects are in the pupa stage they are forming their body parts). Once the female finds these nests she will lay her eggs on or near these chambers or on what will be the hosts. A grub-like velvet ant will emerge from the egg and feed on the body of the host (the wasp or bee pupa) as well as its larvae and will grow to full size in a matter of days. The shell of the host (wasp or bee) then becomes the site to construct a cocoon for the velvet ant pupa and the adult will emerge inthe summer.
The white velvet ant spends time on the creosote bush where it hides between the fuzzy seeds. The red velvet ants are also known as cow killer and mule killer ants and are considered to be so deadly that they can kill livestock. They can sting multiple times and it is believed that their sting can cause the death of cows and mules. But this is just a myth and not true.