Acrobat ants, genus Crematogaster, are a widespread group of ants found globally, with over 400 species documented and 28 in North America. They are named for their distinctive behavior of raising their abdomen when disturbed. This unique posture, along with their appearance, makes them stand out.
Identifying Features
Acrobat ants are small to medium-sized, typically 2.5 to 4 millimeters long, though queens can reach 11 millimeters. Their coloration varies from light brown to black, with some species multi-colored. A distinguishing feature is their heart-shaped or spade-shaped abdomen, also known as the gaster, which appears flattened dorsally. This abdomen connects to the thorax by a two-segmented petiole. They also possess 11-segmented antennae, which aids in their identification.
Their Unique Posture
The common name “acrobat ant” comes from their distinctive behavior of raising their heart-shaped abdomen over their head and thorax when alarmed or threatened. This “acrobatic” stance is a defensive mechanism. When disturbed, they may emit a chemical secretion from the tip of their gaster, often accompanied by a pungent odor. This chemical release deters potential threats, and some species bite aggressively when provoked.
Habitat and Management
Acrobat ants are highly adaptable, establishing nests in various locations. Outdoors, they commonly nest in dead or decaying wood, such as logs, tree stumps, and hollow tree cavities. They can also be found under rocks or in leaf litter. Indoors, these ants are often associated with moisture-damaged wood, nesting in wall voids, insulation, or around windows and door frames. They frequently utilize existing tunnels made by other wood-boring insects, rather than excavating sound wood themselves.
Acrobat ants become a nuisance when entering homes for food or shelter, as their presence often indicates moisture issues; they feed on various items, including insects, honeydew, and proteins. To manage infestations, address moisture problems by fixing leaks and maintaining proper drainage. Sealing entry points like cracks around windows, doors, and utility lines helps prevent them from entering structures. Trimming vegetation away from the house and storing firewood away from the foundation also reduces potential access points and nesting sites. While they can bite, it typically causes only minor irritation and is not considered dangerous to humans.