Velvet ants are popularly known as "cow killers", but this is a fanciful name; they cannot kill animals as large as cows. There are hundreds of species: two of the most well-known are Dasymutilla occidentalis in the eastern USA, and Dasymutilla magnifica, in the western USA.
Note that velvet ants are not ants proper: that is, they are not members of the ant family Formicidae, but are actually wingless wasps in the family Mutillidae.
