California Harvester Ant

Large ants, 1/4 to 1/2 inch long, with a reddish-brown to dark brown body. They have a distinctive large head with powerful mandibles, a rough-textured exoskeleton, and a two-node petiole. Workers are polymorphic (varying sizes).

Diurnal foragers that collect and store seeds. They build large, cleared nest areas with a surrounding ring of pebbles and plant material. They are not aggressive but will sting if handled or if their nest is disturbed. Their sting is very painful and has been compared to a wasp sting.

Open, dry, sandy areas — common in the Antelope Valley and high-desert regions. They build nests in sandy soil in open ground, often in full sun. The nest area is cleared of vegetation and surrounded by a ring of pebbles and seed husks.

Cleared circular areas (3-6 feet wide) in bare soil with a central entrance hole. A ring of pebbles, seed husks, and plant debris around the entrance. Foraging trails radiating from the nest. Dead vegetation around the nest perimeter.

Their sting is extremely painful and can cause swelling and redness lasting hours. Multiple stings can cause more severe reactions. Individuals with allergies may experience anaphylaxis. They are not aggressive and typically only sting when directly handled or trapped against skin.

Identify and mark nest areas in your yard. Wear shoes outdoors, especially in desert areas. Keep children and pets away from nest areas. Do not handle the ants. Reduce bare soil areas by maintaining ground cover. Contact professionals for safe nest removal near the home.