This is a small dark brown/blackish ant that has a faint bluish flash in bright light. Its common name arises from its characteristic erratic and rapid movement. The workers are 2 - 3 mm in size and are notable for their very long legs and antennae. They do not have a sting but can bite and eject a small amount of formic acid. The queens are larger than the workers at about 6 mm and very prolific.
This species is highly adaptable in its nesting habits and can live in both very dry and very wet areas. They are opportune nesters preferring to make use of ready-made cavities such as hollow trees, under loose bark, in rotten wood, under logs or stones, among rubbish and under undisturbed debris like mounds of leaves. They have also adapted to nest in many manmade environments such as inside buildings and even on ships and trains.
Paratrechina originated in Africa. It is a tropical species of ant and has spread to other regions around the world and is now present in North and South America, Africa, Europe, Asia and Australasia. Because of its ability to live in disturbed and artificial habitats such as inside buildings, it has been able to spread northwards to Estonia and Sweden and southwards to New Zealand. Although they prefer warm tropical habitats they can survive and breed at normal room temperature.
Like many successful invasive species, they will utilize a wide range of food including seeds, dead insects, honeydew, plant secretions, fruit and a range of household scraps. In buildings, they collect crumbs and any insect corpses found under lights. Although they usually forage individually, large food items will be moved by several ants working together.
Colonies will produce alates over several months during the rainy season, and on a warm damp evening, the males will emerge from the nest and congregate on the ground or nearby plants. Then as the females emerge, they will mate with them just outside the nest. Many of the fertilized queens will then re-enter their mother nest, although a few will also fly off to start their own colonies.
Rather than expand into a very large single colony they will continually send out ‘colonizing units’ of queens and a few hundred workers to create new subcolonies nearby. This enables them to take over new territory and food sources. These subcolonies are all connected and can form interlinked supercolonies with hundreds of queens and thousands of workers.
With its ability to breed very quick and to utilize many different food sources, it is able to invade and colonize new habitats very quickly and will overcome its opponents by sheer numbers. Their colonization strategy is not to directly fight opposing species, but to gradually steal and consolidate the other species food sources, and as food becomes scarce the opposing species can raise less brood, and their colonies regress, and will then either collapse or move elsewhere.
One reason why this species has been so successful in colonization is that the new queens are able to mate with their siblings without showing any of the normal negative effects of inbreeding. Although the fertile queens produce workers through normal sexual means, their daughter queens are her genetic clones and the males are all the genetic clones of her original mate. The male and female gene pools thus remain completely separate. This has allowed them to colonize and spread over new areas from a single queen/colony, which then breeds within itself without suffering the usual problems with inbreeding. This tactic has enabled them to become one of the most widespread invasive species in the tropics.
Summary: Because of their adaptable nesting habits they will take to almost any kind of artificial nest, and as they take a wide range of food, they are easy to feed. They will also breed quickly and produce alates within a year, and unlike many other exotic species, the alates will mate in the outworld, and then re-enter the colony. Because of their ability to accept homegrown queens back into the colony - colonies in captivity can become very large, and can in effect last forever!