Solenopsis invicta was introduced from South America into Alabama in 1918, and has been gradually spreading throughout the Southeast ever since. The species is highly aggressive when a nest is disturbed, pouring out of every orifice of the colony. They inflict a painful sting, which induces welts on the skin. Further South, the colonies can be enormous and this species has become a major pest. In the Duke University area, their nests look like broad mounds of loose soil raised a few inches aboveground. Numerous colonies can be seen along the sidewalks of Circuit Drive and Science Drive on the Duke Campus.
(2) Triplehorn, C.A. and N.F. Johnson, Borror and Delong’s Introduction to the Study of Insects, 7th ed., (2005), Thomson Brooks/Cole.