Not all ants can use acids, however, the species known as "crazy ants" are able to use acids to protect themselves from fire ants. They make the acid internally in the abdomen, and the acid is brought up through the mouth and layered onto their bodies.
This ability to make acid and secrete it onto the body protects the crazy ants from the poison that the fire ants can deliver. Researchers found that when studied, the crazy ants had a 98 percent survival rate. Crazy ants are now beginning to take control of certain areas of the United States where the fire ants used to populate. The crazy ant was not a species that was local to the U.S., but it is quickly becoming a dominant species.