How To Recognize And Control Longhorn Crazy Ants That Frequently Establish Indoor Nests And Invade Pantries

Paratrechina longicornis, or the “longhorn crazy ant,” as the species is more commonly known, is a common indoor ant pest found throughout much of the United States. These ants are occasional indoor pests in the south, and chronic indoor pests in the north, including New York state. Longhorn crazy ants seem to prefer dwelling in urban and suburban areas as opposed to non-disturbed rural landscapes, and they readily establish nests within homes, usually within inaccessible areas like wall voids and beneath flooring. This ant species is what is known as a “tramp ant,” which are ants that have hitchhiked to numerous areas throughout the world where they have successfully established thriving non-native habitats. Naturally, tramp ants are the most common ant pests in every region where they have become established, and most experts agree that the longhorn crazy ant is the most widely distributed ant species in the world behind the Pharaoh ant, another common indoor pest.

Longhorn crazy ants have a distinct appearance, which makes them relatively easy to identify despite their small size. Brown to black workers are between 2 and 3 mm in length, and their body is covered in long hairs that can clearly be seen under magnification. A faint bluish iridescence to their bodies can often be seen with the naked eye, and their legs are noticeably long. Although longhorn crazy ants lack a stinger, they are known to bite humans when they become disturbed. Unfortunately, these ants also spray irritating formic acid into the bite wounds they inflict, but longhorn crazy ants are merely a nuisance, and they are not considered medically significant.

Longhorn crazy ants are very common pests throughout New York state where they have been found infesting the top floors of high-rise buildings. Like all tramp ants, longhorn crazy ants are highly adaptable, which is made clear by their ability to establish nests in a variety of both dry and moist indoor locations, including decayed woodwork, wall voids, plant stems and attic spaces. Keeping floors and counters free of food crumbs and sealing cracks, crevices and other potential entry points on the exterior walls of homes will prevent these ant pests from invading homes. The most common indoor methods of controlling these ants include baits, dusts, and spot treatments with residual sprays.

Have you ever sustained an ant bite within your home?