similar to the other chemical signals, this odor trail is also specific to each species. Migration can be caused by unexpected environmental factors such as flooding or establishment of new colonies by new queens. Parasitic enemies Ants S. saevissima is said to be a host species for the parasitic ant species, S. hostilis, although no extensive studies have seen conducted in this host-parasite relationship. Also, S. hostilis has not been collected since its characterization in 1959. Phorids At least 17 species of phorids are known to parasitize the workers of the S. saevissima species group. S. saevissima is reported to be attacked by more phorids than any other type of fire ants. The adult female phorid flies inject their eggs into the thorax of the workers. Then, the maggots decapitate the heads of the ants and eat away their brain. Phorids are especially likely to parasitize workers either during the mating flights of the queen or stalking them during forage. In defense to phorids, fire ants evolved underground foraging tunnels. Apodicrania termophila, a species of phorid fly, attacks certain South American fire ants, although it is ambiguous as to whether it attacks S. saevissima because part of its life is spent being cared for by the ants. Habitat and distribution Habitat S. saevissima is native to the tropical and warm climate regions of South America, especially eastern Brazil (Pelotas). It is commonly found in the disturbed areas of grasslands and forest openings due to its workers' nature as excellent recolonizers. These disturbed sites can be manmade (farms or plantation) or natural (animal trails and riverbanks). S. saevissima prefers to build its colonies in sandy soil rather than clays. Mounds can reach up to 10 feet in length and have over one million residents. Distribution S. saevissima has been mostly restricted in the eastern half of South America, with rare imports to Africa and the Galápagos Islands. It was reported in Guinea in the 1920s and Kenya in 1911, but there has been no recent collections. So far, it has not been imported into the United States. Sting Venom Ants belonging to the genus Solenopsis are known as "fire ants" because of the pain caused by their stings, which inject venoms. The venoms of fire ants are characterized by a variety of alkaloids known as solenopsins (2-methyl-6-alkylpiperidines) that exhibit necrotic, hemolytic, antibiotic, and toxic properties. These venoms have very small amounts