Fire ants obtained their name because their bite causes a burning sensation. Disturbing a nest of fire ants can result in a mass attack from the fire ants so it's important to get far away from the concentration of the ants before treating the bite. Even though they bite it is the venom from their sting that causes the discomfort. Fortunately they are easy to treat; however, if the swelling persists or if your pet was stung by multiple ants it's a good idea to have your pet checked out by a vet.