Velvet ants are not ants but rather a type of wasp found worldwide, especially in desert and sandy areas. They get their name because they look like large hairy ants, especially the wingless female (males have wings). Velvet ants are normally nonaggressive.

Velvet ant venom, like other wasp venom, is similar to bee venom, but the venoms are generally not cross-reactive. Velvet ant venom contains enzymes, small peptides, and amines. The allergens include the phospholipases, hyaluronidases, and cholinesterases. Some peptides cause histamine release by degranulating mast cells. Histamine, serotonin, and acetylcholine contribute to the pain associated with velvet ant stings.

The sting of a velvet ant is excruciatingly painful and causes localized redness and swelling.

There are no reports in the literature of anaphylaxis from a velvet ant sting, although, in theory, anaphylaxis is possible.