The imported fire ant, Solenopsis saevissima var richteri, first appeared near Mobile, Ala, around 1930, and is now found throughout the Southeastern United States. Solenamine, the active fraction of fire ant venom, is a potent necrotoxic agent. Imported fire ant stings produce characteristic pustular lesions which often are arranged in a circular pattern. Thousands of these lesions may be seen in alcoholics who inadvertently disturb a fire ant mound.