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.

When the longhorn crazy ant (Paratrechina longicornis) bends its abdomen while aiming at an enemy insect, it is typically shooting its hard-to-see acid.

The worker longhorn crazy ant is about 2.3 to 3.0 mm (0.09 to 0.12 in) long with a brownish-black head, thorax, petiole, and gaster, often with a faint blue iridescence.

[3] It has spread to temperate regions around the world, and due to human interference, is now present in North and South America, Africa, Europe, Asia, and Oceania.

It is a tropical species, but because of its ability to live in disturbed and artificial habitats, inside buildings, and in urban areas, it has been able to spread northwards to Estonia and Sweden and southwards to New Zealand.

The ants are omnivorous and feed on seeds, dead invertebrates, honeydew, plant secretions, fruit, and a range of household scraps.

They consume honeydew predominantly in spring and autumn, and may tend aphids, mealybugs, and scale insects so as to maximise the secretions they produce.

It fed almost exclusively on the honeydew secreted by the large numbers of scale insects and mealybugs present, and other invertebrates were greatly diminished.

Meanwhile, the workers congregate on nearby vegetation, and periodically, a wingless female comes out of the nest, although mating is difficult to observe in the constantly moving mass of ants.

The male and female gene pools thus remain completely separate (assuming workers never reproduce), and this has allowed the longhorn crazy ant to become one of the most widespread invasive species in the tropics.