The Allegheny mound ant, Formica exsectoides (Forel), has a reddish head and mid-section and a black or brown abdomen. It nests in soil and makes a mound on the surface. Many people, who find the mound and see the ants, think that fire ants have moved into the area.
Unlike the fire ants, the Allegheny mound ant does not sting. The workers will bite if the mound is disturbed. Fire ant workers attack in large numbers. They bite and sting aggressively.
Allegheny mound ants are members of a group known as “Field ants”. There are several other field ant species around the U.S. Some of these field ants can be confused with some other type of ants. The black field ant is often mistaken for the black carpenter ant. A closer look reveals the difference between the ants, but homeowners are startled to think they might have structure-infesting ants.
As the name suggests, Allegheny mound ants are distributed throughout the Allegheny Mountains. They are common from Nova Scotia to Georgia. They have been found as far west as Iowa and Wisconsin. The Allegheny mound ants eat honeydew. The workers care for aphids to get the honeydew. The ants also eat insects. The workers rarely enter homes, but they commonly forage on decks and patios for food that has been dropped.
Allegheny mound ants make their nests in the ground. As they dig the galleries, the workers make a mound on top of the ground. There are reports of mounds as high as 36″ and as wide as 13'. There may be hundreds of queens in a colony. The workers often build satellite mounds and connect them with tunnels.
Workers of the Allegheny mound ant often make the nest under shrubs or ground-covering plants. There are reports of the workers damaging shrubs and young trees by chewing the bark.