Paratrechina longicornis, or the “black crazy ant,” as the species is more commonly known, can be found living in close association with humans in virtually every human-populated region in the world, and only the Pharaoh ant may be more widespread. Black crazy ants are sometimes referred to as “longhorn crazy ants,” and they are commonly confused with other invasive crazy ant species, particularly the Tawny crazy ant pest found in the southern states. Just like their Tawny crazy ant relatives, black crazy ants are relatively easy to recognize on account of their erratic and fast movements. Unlike the Tawny crazy ant, the black crazy ant is abundant in the northeastern states as well as the southern states.
Due to the cold northeastern winters, many entomologists believe that black crazy ants can only survive in the region by maintaining a constant indoor habitat where they are known to establish nests within wall voids and other inaccessible or well concealed areas. Due to the large size of colonies, the small size of workers, their ability to adapt to a variety of indoor and outdoor conditions, their habit of foraging long distances from their nests, their lack of interest in baits and their ability to rapidly transport nests to new areas, black crazy ants are considered by many pest control professionals to be one of the most challenging ant pest species to control.
In addition to being hard to control, black crazy ant workers can be aggressive toward humans, and while they cannot sting, workers are known to bite humans before spraying corrosive formic acid into the bite wound. Instead of a stinger, Formica ants and certain other ant species possess what is known as an acedapore, which is where formic acid is secreted. The formic acid secreted by crazy ants has been known to blind humans when the irritating substance makes contact with the eyes, but yellow crazy ants from Australia are responsible for most of these cases. Black crazy ants frequently establish multiple indoor nests in Massachusetts, and these ants and their nests have even been found at the top of high-rise buildings in Boston.
Were you aware that certain ant species were capable of spraying acid for defensive purposes?