The longhorn crazy ant (Paratrechina longicornis), also known as "black crazy ant", is a species of small, dark-coloured insect in the family Formicidae. These ants are commonly called "crazy ants" because instead of following straight lines, they dash around erratically. They have a broad distribution, including much of the tropics and subtropics, and are also found in buildings in more temperate regions, making them one of the most widespread ant species in the world. This species, as well as all others in the ant subfamily Formicinae, cannot sting. However, this species can fire/shoot a formic acid spray from its abdomen when under attack by other insects or attacking other insects. When the longhorn crazy ant (Paratrechina longicornis) bends its abdomen while aiming at an enemy insect, it is most likely shooting its hard-to-see acid. This acid is normally not used on humans and normally does not affect humans. The black crazy ant can not harm humans in any way. These ants can be touched safely just like the common ghost ants.