Field ants are known for producing large mounds of dirt that can be responsible for ruining the appearance of lawns, inhibiting turf growth and cause difficulties with lawn care including mowing. Mounds are frequently three to four feet in width and up to two feet in height. Not only do the mounds cause problems for the surrounding lawn, these ants are known for killing woody and herbaceous plants that shade their mounds by injecting formic acid directly into the plant’s roots. Medium to large ants, most field ants range from 1/5 to 3/8 of an inch in length. Coloration varies depending on the species from black to a mixture of black and red. Field ants are known for inflicting painful bites to both people and pets when disturbed.
Field ant colonies are capable of surviving 10 or more years. These ants do NOT invade indoors in search of food. Their food source is collected exclusively outdoors where they feed on honeydew from aphids along with live and dead insects. Colonies consist of a single queen, responsible for production of all the eggs which hatch into sterile female workers and male drones. Queens may be as deep as two to three feet within the colony, which can make treatment difficult. Standard surface treatments are typically unsuccessful as they do little to eradicate the queen. Pest control professionals typically have the knowledge and equipment necessary to inject insecticides directly into the colony or to utilize a drenching method from the surface in order to increase the likelihood of eliminating the queen within the colony. Often times this requires the dirt mound to be raked aside and probe tunnels to be created prior to treatment. Studies have shown that hot water and borax type treatments are ineffective against field ants.