Red Imported Fire Ant

Adult Red Imported Fire Ants range in color from yellow to reddish-brown to black. These lawn pests have large eyes and four teeth on their mandibles. Adult fire ants also have two nodes (bumps) in the constriction that joins the thorax to the abdomen, and elbowed antennae that are broken into 10 segments. Worker fire ants can significantly vary in size. They are extremely territorial and aggressive—workers swarm out of their nest to attack if disturbed. When these lawn pests attack, each individual fire ant will grip an insect, animal or human's skin with its mouthparts and then inject a toxin using their abdominal stinger. This sting may cause a burning and itching sensation or, in more severe cases, serious welts or allergic shock. Signs of Red Imported Fire Ant damage in lawns appear as wilted, yellow-brown patches of grass that may coalesce if there is a severe fire ant infestation. Symptoms are first seen in stressed grass along sidewalks or driveways, especially during hot, dry weather. Actual fire ant damage to grass is a result of the loss of sap inside the plant, as well as toxins released by the lawn pest that disrupt the vascular system. Drought stress can often mask the damage caused by this lawn insect. Red Imported Fire Ants do not feed on lawns. Rather, these lawn pests prey on other insects and dead animals. However, the mounds they build to warm eggs, larvae and pupae are unsightly and cause damage to grass. These mounds can reach up to 2 feet in diameter and up to 8 inches tall. Damage to grass occurs when persistent mounds cover the turf and block out the sun.