Global menu

Insects and other arthropods

Pharaoh ants

Monomorium pharaonis

Tabs group


These are very small ants, varying in colour from pale yellow to brown, with a darker abdomen. The petiole, the part that gives ants their slender waists, has two small nodes.

Adults in the colony belong to different castes. Workers are sterile females from 1.5 to 2.5 mm long. Queens, larger and darker, are from 3.5 to 5 mm. A single colony may have several queens. Males are about 2.8 mm long. Queens and adult males have wings when they emerge.

Life cycle

Pharaoh ants live in huge colonies, some with more than 300,000 members. Queens and males mate in the nest; there is no mating flight. Males die within a few days of mating.

A queen’s abdomen contains a spermatheca, an organ where she stores live sperm. After mating, queens lose their wings and begin laying eggs. They continue laying for the rest of their lives. Each queen produces some 400 eggs over the span of her lifetime, lasting about 200 days. Females (workers or queens) hatch from fertilized eggs, and males from unfertilized ones.

A legless larva emerges from the egg and is fed by the workers. The larva turns into a prepupa and then a pupa and finally an adult, 38 days after the egg is laid. The workers supply the colony with food, tend the young ants and the queen, and defend the nest.

New nests are formed when a group of workers moves part of the brood to another nesting site. These satellite colonies often remain in contact with the mother colony when they are in the same building. A colony generally has more than one queen, and sometimes several.

Geographic distribution

These ants are found almost worldwide. They probably originated in tropical Africa, and were introduced to North America via Europe.

Add this