A feisty little Argentine ant (Linepithema humile) attacks a much larger fire ant (Solenopsis invicta). Both species co-exist naturally in subtropical South America, but in the southern United States where both have been accidentally introduced, the fire ant has displaced the Argentine ants. Austin, Texas, USA
A ancient antagony between two highly competitive ants (Linepithema humile and Solenopsis invicta) from the same river basin in South America plays out again in North America where both have been introduced. Austin, Texas, USA
Fire ants may have taken over Texas, but the invasive population is not harmonious. Here, workers have pinned down an ant from a rival colony, who defends herself with her stinger. Bastrop State Park, Texas, USA.