Jennifer Zee (MS 2003) investigated nest-raiding behavior of the Argentine ant. Raids blur the distinction between predation and competition, and contribute to the Argentine antís ability to displace native ants. The disappearance of seed-eating harvester ants from areas with high Argentine ant densities seems especially likely to be the result of nest raiding because the Argentine ant and most harvester ant species largely consume different types of food. Incipient harvester ant colonies appear most vulnerable to marauding raids.
Zee J and DA Holway. 2006. Nest raiding by the invasive Argentine ant on colonies of the harvester ant, Pogonomymex subnitidus. Insectes Sociaux. 53:161-167.