In the natural environment, ants are essential components of a balanced ecosystem due to their habit of tunneling through soil, which allows rainwater, oxygen and nutrients to be absorbed by plant roots. Unfortunately, in human environments, many ant species are considered a nuisance, and some pest species pose a medical threat to humans, while others inflict costly damage to structural wood in homes.

More than 12,000 ant species have been documented worldwide, but only a small minority of these species are considered pests. Ant species in Louisiana are particularly abundant and diverse, as most of the world’s ant species thrive within subtropical regions where the climate is characterized by frequent bouts of rainfall and high humidity. Of course, the state is also home to numerous ant pest species, including pavement ants, odorous house ants, and Pharaoh ants, as well as several invasive ant species, most notably red-imported fire ants and Argentine ants.

When a home becomes infested with ants, pest control professionals must first accurately identify the ant species in order to select the proper method of control. Ants generally prefer to establish nests outdoors, but if a home contains superior shelter and easily accessible food sources, they are likely to establish indoor nests. Many ant pest species can establish nests both indoors and outdoors, while others can only establish nests outdoors. Multiple indoor nests are almost always secondary nests, which are referred to as “satellite nests,” while the primary nest, or “parent nest,” is generally located outdoors in close proximity to the infested home.

The ant pest species that are known for establishing indoor nests include acrobat ants, thief ants, odorous house ants, and unfortunately, red-imported fire ants. Red-imported fire ants establish extensive nests within residential yards more often than in homes, and destructive carpenter ants establish nests in wall voids, within structural wood, or both. The Pharaoh ant is one of very few ant pest species in Louisiana that establish nests almost exclusively indoors, and their nests are usually located within hard-to-access areas located near heat and moisture sources. Argentine ants, little black ants, crazy ants and a variety of tramp ants rarely nest within homes; instead, their nests are most often found near trash piles, beneath pavement, in lawn soil, and in the case of little black ants, within rotten and/or decayed natural wood sources in yards.

Have you ever located red-imported fire ant nests on your lawn grass?