A cluster of fire ants.
any of a genus (Solenopsis) of ants whose sting causes a burning sensation, esp. a South American species (S. invicta) that has become a severe pest in the S U.S.
Any of various ants of the genus Solenopsis that build large mounds and can inflict a painful sting, especially S. invicta, native to South America and naturalized in the southern United States.
(plural fire ants)