Fire ants: Originally from S. America. Among the worst insect pests ever to invade the US. Red or yellowish ants of small-to-medium size with a severe sting that burns like fire. They normally feed on small insects but, with denser populations, they eat seeds and seedling plants, damage grain and vegetable crops, invade kitchens, attack newly hatched poultry and the young of ground-nesting wild birds. Fire ants can kill newborn domestic and wild animals. Each colony is composed of a queen, winged males and females and 3 kinds of workers. A nest averages about 25,000 workers, but far larger populations are common. Semipermanent nests are large mounds of excavated soil with openings for ventilation. Since nests may number 50-100 (or more) in a heavily infested field, cultivating becomes difficult (or impossible). Fire ants belong to the genus Solenopsis. The severe sting of this ant causes a pustule to form within 24 hours that takes 10-14 days to resolve. Fire ant toxin can trigger an allergic reaction, particularly in people allergic to bee, wasp and yellowjacket stings. Avoidance and prompt treatment are essential.