Fire ants are a variation of giant ants that is even more mutated than the "regular" giant bugs. Their name comes from their ability to literally breathe fire, similarly to the Fire Geckos from the Core Region. The fire ants were created by Doctor Lesko, a Capital Wasteland scientist, and can only be found in the area around Grayditch and Marigold Station. He was attempting to return giant ants to their normal size over a couple of generations through genetic manipulation but as he reasons, one small tweak of an error has left the ants with a completely different mutation.