Usually the ants guarding the mound are much larger than the ants out foraging for food and water. Worker fire ants vary in size with the largest called majors, the medium-sized called medias and the smallest, which make up the majority of the workers, called minors. Fire ants aggressively defend their mound. Each worker ant stings its victim repeatedly. When the fire ant stings, it injects a venom that causes a burning sensation.
Blisters form, end if scratched can become infected.
Some people are allergic to the venom. Watch for symptoms as headaches, dizziness, swelling around the sting, and shortness of breath. If you are severely stung or show allergic symptoms, seek medical attention. These ants may also attack pets, livestock, and wildlife, sometimes blinding or killing young animals and birds that are unable to escape. In some cases, common ants compete with RIFA for food, water, and space.