Attractive and conspicuous, elongate twig ants are tree-dwelling species with a painful sting. They are frequently found singly or in very small groups of individuals.

Identification: Elongate twig ants, Psuedomyrmex gracilis, are long (10-14mm), slender ants that appear to be all the same size. Their eyes are large and obvious. The most common species is black and orange, and locals call it the Halloween ant. Other smaller species are light to dark orange (or yellow) and some are brown (Pest Ants of Louisiana).

Biology: This introduced species nests in twigs, plant cavities and in dead plants. They have small colonies, and rarely more than a few individuals are seen. They will often fall from bushes or trees onto humans or picnic tables. These ants also crawl on humans who walk through tall brush. They are noticed when they inflict their painful sting. Elongate twig ants feed on other insects and honeydew from aphids and other Hemipterous insects. This species makes short, jerking movements that are wasp-like and can be seen beating their antennae repeatedly.

Treatment: Avoiding these ants is best. Watch for these ants during hiking, yard work and picnics. Gently brush them off yourself and surroundings if you encounter these ants. They normally do not sting immediately when they encounter humans.