Crazy Ant

Description: Crazy ant workers are light brown to black with a gray sheen and 1/16 to 1/8 inch long, The thorax has no spines and the petiole has one segment. The distinguishing characteristics of this species are their extremely long legs and the first segment of the antenna which is twice as long as the head. The tip of the abdomen has a circle of tiny hairs.

Biology: Little has been published on the biology of this species. The size of colonies tends to be small, containing less than 2,000 workers. A colony of this size may have eight to 40 queens. Occasionally they completely abandon a nesting site and relocate to another.

Habits: Crazy ants often nest outdoors in soil under objects such as trash, refuse, mulch and stones and in potted plants and cavities in trees and plants. In structures, they nest in wall and floor voids, especially near hot water pipes and heaters.

Their common name relates to their erratic running about in their search for food. They do travel in well established trails, foraging as much as 100 feet from their nest. They feed on honeydew produced by aphids and other plant feeders, seeds, fruit, insects and almost any household food products. They frequently enter structures in the fall or after because both conditions reduce the availability of honeydew outdoors.

Control: All cracks and gaps in exterior walls which provide access to voids or interior areas should be sealed. All debris from the exterior of the structure and other items on the ground where these ants nest should be removed.

Baits are not the most effective method of eliminating crazy ants because their food preferences change quickly. If baits are attempted, they should be placed where ant trails have been established and in locations where the ants have been sited. Unless using containerized baits outdoors, they should be placed so they are inaccessible to children and pets. Sweet baits are the most effective; however, if acceptance is low, consider using a protein bait.

The most effective control is accomplished by following the ant trails, locating the nests and then treating them with a residual insecticide. Exterior nests should be drenched with a liquid formulation. Nests in wall voids are more easily treated by aerosol injection or application of a dust formulation. When the nests can not be located, a microencapsulated or wettable powder formulation should be applied as a barrier spray to foundations and the soil immediately adjacent to the building . This is effective in repelling foraging workers and preventing them from reentering the structure.

Controlling aphids on ornamental plants and trees around structures removes their primary food source and causes them to forage elsewhere for food.