Three species of fire ants inhabit the desert southwest: the Solenopsis xyloni, the Solenopsis aurea and the Solenopsis amblychila. The common name refers to the ants' notoriously nasty sting

Description:

All three species look similar in shape, color and size. Fire ant workers come in two sizes. Minor workers may be as small as 1/10 inch in length. Major workers may measure up to 1/3 inch. Queens are slightly larger than the biggest workers. The S. xyloni generally has a yellowish-red head and a thorax with a black abdomen, known as the gaster. They may also be completely orangish-red or brownish black. California desert species are the reddest. Of the three species, S. xyloni most closely resembles the notorious red imported fire ant, S. invicta, an invasive species which has infested the entire Southeast. S. aurea is more yellowish than the two other species.

Range:

S. xyloni has the widest distribution of the three species, occuring across the southern United States from the Carolinas to Georgia through lowland Tennessee and south-central Kansas to California. S. amblychila has been found in Ramsey Canyon, Arizona, in west Texas, and in the Dona Ana Mountains of southern New Mexico at elevations from 5000 to 8250 feet. S. aurea occurs from Texas to California at elevations below 6600 feet.

Habits and Habitat:

Large colonies of fire ants nest in the soil, often near moist areas, such as river banks, pond edges, watered lawns and highway edges. A single nest, usually less than _ square yard, may have several small openings on the surface or in fissures; no opening is central. The ants shift the entrance during the season and may transport immature ants between openings. Excavated soil is often an irregular and variably shaped mound of loose soil, but it can also form a crater.

Near homes, they may nest at the edge of walks, in cracks in the cement, or adjacent to steps. Inside homes, nests are built in the walls, in the vicinity of kitchens. The ants forage at night, with mostly the smaller workers seeking out food. Larger workers spend little time away from the nest, but they come to the surface quickly when disturbed.

Nuptial flights, when males and queens seek out mates and new nests, occur in the afternoon following a rain storm, from May through September. Colonies are founded by small groups of queens or single queens. Only one queen survives, and within a year or so, the colony expands into thousands of individuals.

Fire ants are well known for their propensity to "boil out of the ground" when their nest is disturbed. They will sting and bite the intruder, causing memorably unpleasant pain.