This species is really tiny (1.5 to 2 mm). Its colour varies from yellow to rust, and like other ants, has a narrow waist and bent (folded) antennae.
In tropical climates, pharaoh ants nest outdoors, in plant cavities. Unlike their cousins, they do not nest in a permanent territory, but depend more on their relationship with man. Workers from other colonies are not chased away, and some young may even be exchanged. Males and queens are produced, but they do not swarm when mating. New locations are colonized when the workers leave with some of the young (eggs, larvae and pupae). Even if no queen accompanies them, the workers are able to develop one from the young. These ants feed on living or dead insects and fatty substances (including shoe polish) or sugars (fruit juice and pastry). They quickly guide other individuals to a source of nourishment by leaving scent trails, and they can contribute to the transportation of microbes.
Places where they can be found in the home
A single box of cookies can provide for the needs of an entire colony. Pharaoh ants are often discovered in the kitchen or bathroom because of the heat and humidity. They can be found inside walls, in the smallest cracks and along pipes, in wardrobes and furniture, between sheets of paper, under the floor, and near the dishwasher. They manage to get into such surprising places as a closed jar with a screw-on lid. They also invade greenhouses, places where food is stored (restaurants, pet shops, zoos) and hospitals.
Ideally, avoid leaving any food or scraps around the house and use hermetically sealed containers. Plugging up cracks in the house can also help.
It sometimes requires patience to get rid of these ants because the most effective measures are not necessarily the fastest, and the situation must be closely monitored since there are often several nests. We also need to know what we are doing; using a poorly chosen insecticide can break up a large colony into several smaller ones. Workers may be incited to take some young with them, with or without a queen, to colonize a new location. Researchers have made, and continue to make, a great effort to discover ways to control this insect with its highly-varied and often hard-to-find nesting sites, the existence of which is not always obvious. Studying their food preferences has helped develop baits that can be used to detect their presence. Foods they enjoy are placed along the scent trails they use for their movements. Sometimes it is necessary to change the bait. A chemical that will be carried back to the nest and exchanged with the whole colony can then be added to the bait. They even have synthesized chemicals that prevent them from developing into adults or render them sterile.
It is false to think that small ants are young ones that will become like the larger ones, when in fact they are different species. When immature, ants initially resemble white worms. They then take on the appearance of adults, but still keep their white coloration.