Several ant species belonging to the Acanthomyops genus are common pests of homes and buildings in the northeast. The smaller yellow ant, the larger yellow ant, and Acanthomyops latipes, the last of which has not yet been given a common name, are the most frequently encountered species of this ant genus in and around homes. Acanthomyops ants are also commonly referred to as citronella ants due to the reportedly pleasant lemony odor of their alarm pheromones, which become noticeable when the ants are disturbed or crushed. While most ant pest species see workers forage into homes from nests located outdoors, indoors, or both, workers of the Acanthomyops genus don’t typically invade indoor living spaces; instead, these ants are known for invading homes as reproductive swarmers, or “alates,” as they are known among professional entomologists and pest control professionals.

Workers of the smaller and larger yellow ant species are between 3-4 mm and 4-4.5 mm, respectively, while A. laticeps workers average 3.7 mm in size. All workers belonging to Acanthomyops species are shiny and light brown to yellowish brown in color, and they are known for establishing nests directly against the foundation walls of homes. In addition to nesting within soil against foundations, these ants often establish nests within the cement and brick masonry that make up foundations. Central heating allows Acanthomyops ants that nest near or within foundations to remain active during the colder months.

Generally, winged alates emerge from colony nests during the late summer and early fall seasons, and given their habit of nesting near and within foundations, large nuisance swarms often appear in basements and ground level living areas during this time of year. However, alates from Acanthomyops ant colonies are known for emerging at various and unpredictable times of year, and it is not uncommon for swarms to emerge within homes during the winter, even in the northeast. While foraging workers from both smaller and larger yellow ant colonies sometimes invade indoor living spaces, it is particularly rare for A. laticep workers to invade homes, but all three species frequently swarm within homes. Swarming alates resemble workers, but alates are twice the size of workers and possess wings. Indoor Acanthomyops ant swarms are often mistaken for termite swarms by homeowners.

Have you ever encountered an active ant swarm within your home?