The pharaoh ant is native to Africa and was named in 1758 by Linnaeus using a type specimen from Egypt. In naming this ant, Linnaeus may have been under the impression that it was one of the ten plagues of Egypt. It has been a worldwide pest (or plague) for over 100 years and is historically well-known for infesting structures. Being a tropical ant species, it can nest outdoors in soil in subtropical areas. In temperate regions, it mainly nests inside heated structures because it cannot survive outdoors year-round.
Indoor pharaoh ant populations are difficult to manage because they nest in hard-to-find voids. They also reproduce by mating within nests and budding into additional nests. This process can produce multi-floor infestations in large buildings. In medical facilities, pharaoh ants can contaminate sterile supplies and patient wounds if certain bacterial pathogens are present on their bodies. For this reason, the EPA requires additional efficacy data from manufacturers during registration in order to include pharaoh ants as a target pest on a product label.
Applying repellent insecticides to pharaoh ant colonies causes them to bud and move to new areas, making infestations worse. Ant baits have traditionally been relied upon to manage pharaoh ants. Baits need to be applied near foraging trails and routinely monitored for acceptance. Non-repellent liquid residual products specifically labeled for pharaoh ants are also available. These products can be applied to foraging trails and structural voids where pharaoh ants are nesting.