The acrobat ant gets its common name from raising its abdomen over its thorax and head when disturbed. These ants, which are actually several species, will bite on occasion and will give off a repulsive odor when disturbed.
Most acrobat ants are black to light brown, but a few are multicolored with the head or abdomen darker than the rest of the body. Most species are 1/16 to 1/8 inch long. The workers in each colony are monomorphic, which means they are all similar in size. One clue for identification is that they have a 2-segmented section called a petiole that attaches to the front portion of the abdomen with a pair of spines on the thorax. The abdomen is shaped like a heart and is best viewed from above.
Biology and Habits
Outdoors, acrobat ants can feed on honeydew from aphids, mealybugs, and live or dead insects. They are typically found under rocks, or in logs, firewood, and trees. These ants prefer nesting in moist wood softened by decay or fungi. Occasionally, acrobat ants will strip the insulation from electrical or telephone wires causing short circuits.
Inside a structure, acrobat ants can feed on sweets and high-protein foods (meats). They may nest in wall voids, baseboards, or door and window framing particularly if it has been damaged by moisture or previously infested with other insects. They may even enlarge cavities formed by other insects such as old galleries of termites, carpenter ants, and other wood-infesting insects. Rigid board insulation used to construct walls of many newer homes also is an attractive nesting site for acrobat ants.
When infestations of acrobat ants are found in a home, they usually entered along electrical and telephone lines, tree limbs in contact with the structure, or fences and decks. However, these ants also can enter a home through many small entry points around doors, windows, and vents.
Successful control of acrobat ants depends on a thorough inspection and correct identification. Nest removal is always the most effective ant management strategy. Both interior and exterior inspections are necessary. The ants inside may originate from an outdoor nest site. Inside a structure, detection of acrobat ant nests can be difficult. Look for small holes, moisture damage and areas previously infested with other wood-nesting insects. One sign may be the accumulation of debris the ants throw out, especially if the colony is infesting rigid board insulation.
If nests in a structure cannot be removed, sprays or dusts can be used effectively if applied directly into the nest. Consider using aerosol sprays that have a straw attachment or dust applicators with a directional tip for crevice application. Ant baits may be effective if placed in areas where acrobat ants are found. Make sure the ants are feeding on the baits and allow the ants to feed for several days to return the bait toxicants to their nests. Do not spray areas where baits are used. Finally, keep food in tightly sealed containers to prevent acrobat ants from foraging for food inside.
Infestations entering from outdoor locations can be discouraged by trimming tree and shrubbery branches so that they are not touching the structure and providing a direct path to enter. Seal cracks and crevices in the foundation. Trees holes with acrobat ant nests may be injected with a dust or aerosol insecticide. If outdoor nests cannot be located, spot treatments with baits or insecticides at entry points around the structure can be helpful. If an area is heavily infested, a perimeter treatment by a pest control professional may be required. Always follow label directions.
Originally published 04/04