Pharaoh Ants, believed to be a possible native of Africa, nests outdoors only in southern latitudes. In colder climates, they have adapted to living inside of heated buildings. Nesting occurs in inaccessible, warm, moist areas near sources of food and/or water. Colony sizes tend to be large when well established, with individuals reaching in numbers up to several hundred thousand at times under ideal conditions. Colonies consist of queens, males, workers and immature stages. Males are not often found in the colony and die off within 3-5 weeks of mating. They are black in color, have straight antennae and are roughly 2 mm in length. Queens are larger in size at roughly 4mm in length and are slightly darker than their workers. They live on average four to twelve months and produce 400 or more eggs in batches of 10 to 12. Males and queens usually take 42 days to develop from egg to adult. Unlike a many other ant species, mating occurs within the colony and not in swarms. Pharaoh ant workers are monomorphic (same size), but they can vary slightly in length from 1.5 to 2 mm. Body color ranges from yellowish to light brown to red with the abdomen often darker to nearly black. Workers require about 38 days developing from egg to adult. A stinger is present, but is rarely utilized.
A major indoor pest in the United States, the Pharaoh ant is a pest of residential homes, apartments, commercial bakeries, factories, hospitals and any other location where food is handled. Hospitals in both Europe and the United States have experienced infestations, which created an increased risk to patients as Pharaoh ants can transmit over a dozen pathogens including salmonella, staphylococcus and streptococcus. Workers of the Pharaoh ant can often be observed along feeding trails and may use wiring or hot water pipes to gain access through walls and between floors. Workers that locate a food source lay a chemical trail from the food to the nest. Consuming a wide variety of foods, Pharaoh ants are attracted to sweet, fatty and oily foods. Their ability to get into foods results in foods, sometimes in large quantities, being discarded due to potential contamination.
Pharaoh Ants are often confused with thief ants, bigheaded ants, fire ants and several other species of small pale ants, which can contribute to difficulties in control due to improper identification. Non-repellent insecticidal baits are primarily the preferred method of treatment as repellent type products often result in the colony fracturing and budding to a new location, worsening the situation. Entire buildings, especially apartments, are typically treated when a Pharaoh ant infestation is determined to be present. Control may take months and repeated follow up treatments are common. Hiring a pest control professional with experience in treating Pharaoh ants is strongly recommended as home treatments are likely to make the situation worse.