“The ants seek hollowed-out cavities of plant material like dead twigs and small branches in order to house their small, single-queen nests. Some of the more typical habitats include rainforests, mangroves, fields that have reverted to secondary growth plants and hardwood trees. Nests have only one, small entrance and may be inhabited by only a few ants. Elongate twig ants excavate nesting cavities themselves if the nesting material is flexible and soft and will also nest in tunnels made wood boring beetles.
Elongate twig ants do not create pheromones to aid in nest relocation. Instead, when they need to move and create another nest, adult workers carry other mature workers, queens and males to the new nest site.
There is little or no ornamental plant or structural damage caused by elongate twig ants, even though these ants have rarely been found nesting in wooden doors inside homes.
Pseudomyrmex gracilis swarms and stings enemy nest invaders. This behavior is important since the elongate twig ant is considered a beneficial insect as a result of preying on pest insects and defending its nest. Unlike many other kinds of ants, elongate twig ants are solitary hunters.”