There are several species of acrobat ants in the United States. The most common species in the Kansas City area is Crematogaster lineolata. Their common name is descriptive of this ant's habit of raising the abdomen over the thorax and head, especially when disturbed.
Acrobat ants have a single queen in the colony and establish their colonies in dead wood in a variety of locations, including partially decayed logs, stumps, dead branches of trees or woodwork in homes, as well as foam panel insulation. The ants commonly infest door and window frames previously damaged by moisture. They also like to infest foam panel insulation.
These ants will build carton sheds on plants to cover aphids and mealybugs. Then they feed on the honeydew these insects produce. Indoors they are attracted to both sweet and greasy foods.
Worker ants are about 1/16-1/8" long, with a single queen ranging up to 3/8" long. Their color is light brown to black. Their antennae contain 11 segments, with the last three forming a club. The thorax has 1 pair of spines on the top. The pedicel is 2-segmented, attached to upper side of gaster. The gaster is heart-shaped from a top view, broadest towards thorax and sharply pointed at rear. A stinger is present. When disturbed, they will raise up their abdomens and ooze pungent formic acid at their attacker.
They prefer wood softened by decay fungi or styrofoam insulation, but may enlarge cavities in Inside structures acrobat ants typically nest in wood which has been subjected to high moisture and fungal decay, the same wood conditions favored by carpenter ants. Similarly, they will nest in styrofoam insulation panels and in wall voids. Outside most species nest under rocks, or in logs, firewood, or trees where decay enables them to tunnel under the bark and/or into the wood. They occasionally will nest in abandoned termite and carpenter ant galleries as well as in old wood borer, powder post beetle, or wood wasp tunnels. Often the only exterior indication of damage is the accumulation of debris expelled by these ants, especially if the debris is styrofoam insulation. They will occasionally strip the insulation from electrical or telephone wires which can cause short circuits.
The workers readily enter structures by trailing along tree limbs and utility lines as well as along the rails of connected fences and decks. They then enter via cracks and holes around utility lines/pipes, window frames, soffits, etc. Workers also will trail across the ground and enter via door thresholds, weep holes, and other openings or cracks. They have been found to trail over 100 feet.
The same treatment techniques that apply to carpenter ants can be used on acrobat ants. Finding and treating their colonies in wall voids and wood can usually control these ants. Drilling small holes and dusting the infested areas with insecticide dusts can effectively treat infested walls and voids that harbor these ants. All colonies found outside should be treated directly with a liquid contact spray. Perimeter and foundation treatments of structures with a liquid insecticide will help prevent outdoor foraging ants from entering. Spray applications to trees where acrobat ants are located are helpful