Several species of small to medium-sized ants are occasional pests in and around the home. One of these is named the acrobat ant because of the way the worker ants carry their abdomens above the rest of the body as if they were performing a balancing act. Acrobat ants are slightly longer than 1/8th inch. They vary in color from yellowish brown to dark brown, and the heart-shaped abdomen is usually darker than the rest of the body. Magnification is required to see a pair of spines on the back edge of the middle section of the body that helps identify this ant from other species. The habit of the workers to carry their abdomens in the air when they are disturbed is probably the best way to identify this species.
Acrobat ants may nest both outdoors and indoors. Outdoor nests are most often in dead and decaying wood such as logs, stumps, dead trees limbs, firewood and hollow tree cavities. They may nest in the damp soil beneath leaf litter or rocks. The small worker ants readily enter buildings through cracks around windows and doors and other openings. Trails of workers may be seen moving between the nest and a food source. Acrobat ants feed on a variety of foods, including other insects and sweets.
When acrobat ants nest indoors they are usually inside wood or cavities kept moist with water from leaks. They may also nest in foam insulating board or sheathing. As they excavate the large galleries used as nest sites, sawdust may be deposited near the nest area.
Like all ants, the acrobat ants may produce winged, reproductive individuals (males and females) called swarmers. These sexually developed adults emerge from an established colony, usually in the fall, to disperse and start new colonies. The swarmers are harmless, but they may be the first indication of an infestation. Special treatment of swarmers beyond vacuuming or sweeping them up is not required.
Acrobat ants entering from outdoors can be managed by sealing the exterior cracks through which they enter, using a residual insecticide barrier along the foundation, or by treating the ant nest if the location can be determined through careful inspection and observation. Ant colonies living within the walls should be treated by eliminating any moisture problems (if present) and by injecting household insecticide spray or dust into infested wall voids. It may be necessary to drill small holes to accomplish this treatment. Insecticides containing pyrethroids are available to homeowners for outdoor use. Always follow labeled directs. Please read this article for more information. Insecticides for use indoors are in ready-to-use formulations. Visit your local retailer to find a ready-to-use insecticide labeled for ants. Read and follow the directions on the label. For more information on household insecticides please consult this article.