Nylanderia vividula, or “Nylander’s crazy ant,” as the species is commonly known, is an indoor ant pest from Mexico that has become very prevalent in the Gulf Coast states. These ants have been introduced to a variety of habitats, as they naturally colonize mulch piles and potted plants that are shipped throughout the world. The Nylander’s crazy ant has seemingly thrived within every ecoregion where it has been introduced, and they favor manmade settings where the ants readily nest in grass and frequently invade buildings and homes to seek out food sources. This species has been documented in environments as varied as Finland, the Pacific Islands, New Zealand and Canada, and experts believe that Nylander’s crazy ants are uniquely able to thrive unnoticed for long periods of time within manmade habitats. This is likely due to the fact that researchers usually encounter Nylander’s crazy ants in odd areas where no other ant species can be found.

In the natural environment, Nylander’s crazy ants generally nest in soil below rocks, in leaf litter, and in acorns, but they are able to establish reproductive populations indoors as well. In its tropical to subtropical native North American range, reproductive members of Nylander’s crazy ant colonies often take flight year round. Swarmers (alates) are attracted to lights, so they frequently swarm around and within homes where hundreds or more male and female specimens collect on walls and mate. Unless winters are unseasonably warm and humid, swarms will only occur from May through October, and while the ants are capable of overwintering outdoors, they are known to live exclusively indoors in cooler northern areas. Nylander’s crazy ants workers can be recognized for their yellowish-brown to dark-brown coloring, thick hairs on their head, relatively long legs and antennae, lack of a stinger, and 2 to 3 mm body length. Workers spray formic acid from their abdomen, but they are not dangerous to humans.

Have you ever felt the sensation of being sprayed with formic acid by an ant?