Workers are 1/8 to 3/16 inch long and monomorphic, and queens are 5/16 inch, with yellow, rust, or brownish coloring. Antennae have 12 segments; compound eyes are small; ocelli are nearly absent; 1 node in pedicel; thorax is unevenly rounded; and anal pore has a circle of hairs.

Colonies have only one queen, and swarms may appear in large numbers all at once. Yellow ants prefer sweets and tend aphids, particularly root aphids on the roots of shrubs, and swarms may appear close to structures when shrubs are planted along the foundation.

There are many species with variable sizes, but the larger yellow ant, occasionally a nuisance pest, is common in the Northeast. They prefer damp areas and rotted wood and may become a problem indoors where unattended moisture leaks cause wet conditions, such as behind walls in the bathroom or kitchen. This occurs when winged male and female reproductive inadvertently enter homes through the foundation.