Pest Identification

Learn More About the Pests Invading Your Home

Pest Identification: Cow Killer Ant

Most Common Types


In spite of its name, the cow killer ant is not an ant. It is actually a solitary wasp of the Mutillidae family. It is also known as the red velvet ant or cow killer ant.  


What They Look Like


Both male and female cow killer ants are between 1/2 and 3/4 inch in length. Females look like large ants. They are wingless and have six stilt-like legs. Their bodies are made up of three segments, usually with a wide gap between the middle section and the abdomen. Males look similar to females, only they have a pair of narrow black wings. Both are entirely covered in thick, soft hair that is usually dark red, but may also be yellow, orange, or brown.


Where They Live


Cow killer ants are most common in the Midwestern United States, though their habitat extends all the way to the Eastern seaboard. They are rarely found west of the Rocky Mountains. They are solitary insects and do not live in a colony or hive. Males and females only come together long enough to mate. They are quite shy and will avoid humans and other larger animals whenever possible. They prefer to live in grassy areas with plenty of cover and places to hide, and can most frequently be found crawling through grass, dead leaves, or underbrush.


Where They Nest


Neither male nor female cow killer ants establish nests of their own. However, when the female is ready to lay her eggs, she seeks the immature stages of other ground-nesting insects, like wasps and bees. She lays her eggs directly onto the larvae or pupae of the other insect, so that when her eggs hatch they don’t have to travel far for their first meal.


Steps to Prevent


Cow killer ants generally try to avoid people, so preventative steps are not normally needed. If a cow killer ant accidentally wanders into your home or garage, capture it carefully and place it outside. Do not try to handle them with your bare hands, use a glass or plastic container to catch them. Keep pets and children away from the pest during the capture process to ensure that they don’t get stung.


Are They Dangerous?


Male cow killer ants are virtually harmless, but females are capable of delivering an extremely toxic sting. The sting is very painful and often causes significant swelling. In fact, the common name of the insect comes from a folk saying about the sting being strong enough to “kill a cow.” However, cow killer ants are generally not aggressive and will not sting unless picked up or stepped on.