Pharoah Ant

The Pharaoh ant is polygynous, meaning its colonies contain many queens (up to 200). An individual colony normally contains 1,000–2,500 workers but a high density of nests gives the impression of massive colonies. Colonies also lack nestmate recognition so there is no hostility between neighbouring colonies, which is known as unicoloniality. They produce sexually reproductive individuals roughly twice a year in established colonies but in the laboratory colonies can be manipulated to produce sexuals at any time of year. Colonies proliferate by "budding", where a subset of the colony including queens, workers and brood (eggs, larvae and pupae) leave the main colony for an alternative nest site. Budding is a major factor underlying the invasiveness of Pharaoh ants. A single seed colony can populate a large office block, almost to the exclusion of all other insect pests, in less than six months. Elimination and control are made difficult because multiple colonies can also consolidate into smaller colonies and "weather the storm" of a baiting programme only to repopulate when baiting is withdrawn. Pharaoh ants are a major hazard in hospitals, where their small size means they can access wounds, driplines, and instrumentation, causing the spread of infection and electrical interference.

Pharaoh ants have become a serious pest in hospitals, rest homes, apartment dwellings, hotels, grocery stores, food establishments and other buildings. They feed on a wide variety of foods including jellies, honey, shortening, peanut butter, corn syrup, fruit juices, baked goods, soft drinks, greases, dead insects, toothpaste and even shoe polish. They can also gnaw holes in silk, rayon and rubber goods.