Unlike many ants, the mounds generally lack visible openings, except when the winged individuals emerge. Also in contrast to many ants, IFA do not extensively forage above ground. Instead, most workers travel through a network of shallow, subterranean tunnels. A colony can be a single mound or, in some cases, hundreds of mounds extending over several acres and having thousands of queens. The average colony contains 100,000 - 500,000 workers.
Colonies can begin producing new queens within six months of founding.
IFA largely feed upon insects and other invertebrates, but they also prefer oil-rich seeds and may eat agricultural crops and other plants. IFA can spread over modest distances under their own power. Flooding or heavy irrigation causes IFA to form rafts of workers protecting the queen and brood within, enabling a colony to become established wherever it is deposited by the water. The most important means by which IFA spreads is with human help. IFA was first introduced into this country with cargo from South America.