Fire ant is an ant known for its painful, burning stings. However, not all fire ants are dangerous. There are hundreds of species (kinds) of fire ants. One of these, the red imported fire ant, is a major pest in the southeastern United States and in Australia and Asia. This species builds large, hard dirt mounds that measure up to 2 feet (0.6 meter) high. The mounds can appear in agricultural fields, where they may damage farm machinery. Hundreds of thousands of fire ants may inhabit one mound, and some areas have more than 200 mounds in 1 acre (0.4 hectare). If a person or animal disturbs a mound, the ants swarm out to attack the intruder. The ant’s sting leaves a small, pus-filled, itchy bump that is easily infected. Some people experience severe reactions to fire ant venom, which can be deadly.
Red imported fire ants range in color from red to brown. They measure about 1/4 inch (6 millimeters) long. Red imported fire ants are native to South America. They probably entered the United States by accident aboard freight shipped through Mobile, Alabama, during the 1930’s. These ants arrived without their native parasites and predators (hunting animals). Because of this, few native ant species have been able to compete with them. Red imported fire ants have since spread rapidly and now inhabit an area that stretches from North Carolina to central Texas.
Major efforts have been made to control the spread of red imported fire ants, including the use of parasitic flies that lay their eggs on the ants. After the fly larvae (young) hatch, they eat the ant’s head from the inside out. However, efforts to control the population of fire ants have been largely unsuccessful. The fire ant continues to cause billions of dollars of economic damage in the United States every year. Native species of fire ants in the southeastern United States do not pose major agricultural or health problems.