Red Imported Fire Ants
Red imported fire ants (RIFA, for short) are more aggressive than other ant species and have a painful sting. These ants and their telltale mound nests should be actively avoided. Red imported fire ants can adapt to many climates and conditions in and around their environment. For example, if the colony senses increased water levels in their nests, they will come together and form a huge ball or raft that is able to float on the water!
Alliases:
Solenopsis Invicta Buren
Those Little Red and Black Ants That Really Hurt When They Sting
Red imported fire ants will build their nests in mounds of soil outdoors, in landscape areas or near a building’s foundation. They occasionally enter buildings through holes or cracks in walls and foundations.
The sting of a red imported fire ant is painful and often results in a raised welt that becomes a white blister. Persons allergic to insect stings will react more severely. They are frustrating, not only because of the physical pain they can inflict, but because their mound-building activity can damage plant roots and lead to loss of crops.
For more information see this article from the University of Florida regarding RIFA.