The Pharaoh Ant is a small (2 mm) transparent yellow to red ant with black markings on the abdomen. It's notorious for being a major indoor nuisance pest, especially in hospitals. This is the most persistent and difficult of all household ants to control; with very large colonies, with up to several million workers and thousands of queens.
Each colony of Pharaoh ants produces sexually reproductive individuals roughly twice a year and utilizes 3 types of pheromones. One is a long lasting attractive chemical that is used to build a trail network. It remains detectable even if the ants don’t use the trail for several days.
Each morning, scouts will search for food. When one finds it, it will instantly return to the nest. This causes several ants to follow the successful scout’s trail back to the food source. Soon, a large group will be upon the food. Scouts are thought to use both chemical and visual cues to remain aware of the nest location and find their way.
They can feed on a wide variety of foods including grease, sugary foods, and dead insects. They can also gnaw holes in silk, rayon, and rubber goods. Nests can be very small, making detection even more difficult. They are usually found in wall voids, under floors, or in various types of furniture. In homes, they are often found foraging in bathrooms or near food. Pharaoh ants have become a serious pest in almost every type of building.
Threat To Humans
Pharaoh ants are a major hazard in hospitals, where their small size means they can access wounds and medical instruments, causing the spread of infection and electrical interference.
Eliminating Pharoah Ants
Elimination and control are difficult because multiple colonies can consolidate into smaller colonies during extermination programs only to repopulate later. Pharaoh ants are often exterminated by placing baits, consisting of ground liver mixed with boric acid, in places where the ants forage. Renewing the baits once or twice may be necessary.