Like pavement ants, pharaoh ants belong to the myrmicine ants (Myrmicinae) subfamily, which have two petiole segments between the middle section of the body and the abdomen. The female workers are just 1.5 to 2.5 mm long and amber-yellow in colour. The tip of their abdomen, however, is dark. As the workers are so small, a pharaoh ant infestation is usually only noticeable when they appear en masse.
This species, which originates from the tropics and subtropics, is extremely thermophilic (average temperature of more than 26 °C) and therefore can only be found in well-heated buildings at our latitudes, i.e. primarily in hospitals, bakeries, commercial kitchens, indoor swimming pools, etc.
Pharaoh ant colonies can become very large and normally have several queens. As their nests are concealed and they create branched nests in the brickwork, this makes them exceptionally difficult to combat.
Pharaoh ants primarily feed on foods which contain protein, such as meat, eggs, cheese or blood, as well as sweet foods. As well as being a nuisance, they are also significant as vectors of germs, such as salmonella, streptococci and staphylococci, especially in hospitals and retirement homes. As they are so small, they can enter medical devices, sterile packages and also wound dressings.
Due to their small size, the female workers can also get into electrical devices, like computers, etc., when they are looking for somewhere warm. This can cause cable fires and significant economic losses.