Field Ants

Formica spp.

The common name of the field ant comes from its preference for nesting outdoors. The field ant is the largest genus of ants found north of Mexico. Field ants are also known by many other names such as thatching ants, red ants and wood ants.

Pest Stats


Pale yellowish to reddish brown to black or a combination




Profile unevenly rounded on upper side; segmented


1/8-3/8” (3-9mm)




Found throughout the United States


Field ants can become a pest in late summer when the winged ants swarm out of their colonies.

Field ants primarily feed on honeydew, which is a substance from plant-sucking insects such as aphids, mealy-bugs, and scale insects found on trees and shrubs. However, some species of field ants, including the silky ant, gather groups of aphids so there is always a vast supply of honeydew. Other types of field ants are scavengers and are attracted to meats.


Field ants construct mounds made up of plant materials, such as grass, twigs, leaves and pine needles. They often nest around small trees, shrubs or rocks. Other species build their nests in the cracks of sidewalks, along foundation walls and at the base of trees. Field ants rarely nest in homes but occasionally enter in search of sweets.


Field ants do not have a stinger, but they will bite when disturbed. Some field ants spray formic acid into the wound when they bite, so it can be very painful.