[1] A cryptogenic species, it has now been introduced to virtually every area of the world, including Europe, the Americas, Australasia and Southeast Asia.

[2][3] The ant's common name is possibly derived from the mistaken belief that it was one of the Egyptian (pharaonic) plagues.

Pharaoh ants are a tropical species, but they also thrive in buildings almost anywhere, even in temperate regions provided central heating is present.

From egg to sexual maturity, it takes the pharaoh ant about 38 to 45 days, depending on temperature and relative humidity.

Mature colonies contain several queens, winged males, workers, eggs, larvae, pre-pupae and pupae.

This fact is particularly curious because of the presence of a very aggressive ant family, Iridomyrmex, which is quite proficient at interference competition.

This success can be attributed to their efficient foraging strategy, and their novel use of venom alkaloids, repellant chemical signals.

This pheromone is useful in marking food sources, as these are unpredictable and the colony must be able to respond to environmental changes quickly.

If an individual finds an unprofitable area with little food or significant danger, it will release this repellant pheromone, which will warn others and cause them to look elsewhere.

[13] Like the food source marker, the negative pheromone is volatile, decaying roughly two hours after being emitted.

This causes several ants to follow the successful scout's trail back to the food source.

Scouts are thought to use both chemical and visual cues to remain aware of the nest location and find their way.

[16] If the colony is exploring a new region, they employ a land rush tactic, in which a large number of foragers randomly search, constantly releasing pheromones.

Even inside colonies were found to forage close to windows, indicating a propensity for outdoor environment.

Food deprivation induces a higher amount of foraging ant traffic, compared to a non-deprived population.

When returning to the nest, a forager that encounters a fork will almost always take the path that deviates less from its current direction.

This method of decision-making reduces the wasted energy that would result from traveling in the wrong direction and contributes to the pharaoh ant's efficiency in foraging.

Depending on food availability and each individual's condition, a scout may refuse the queen's entreaties and even run away from her.

[20] If a large amount of larvae results in a surplus of secretions, pharaoh ants will store the excess in the gasters of a unique caste, the replete workers.

The decision to vary the type of food consumed ensures that the colony maintains a balanced diet.

[23] Monomorium pharaonis, similar to other invasive ants, is polygynous, meaning its colonies contain many queens (up to 200).

Conversely, in a large colony, the high worker to queen ratio maximizes the foraging capacity of the nest, helping sustain the population size.

[25] The pharaoh ant is a polygynous species that has a relatively low worker to queen ratio of around 12.86.

[27] To branch out and form a new bud nest, pharaoh ants need a minimum of 469 ± 28 individuals, which explains how they proliferate so quickly.

[28] Mating for pharaoh ants occurs within the nests with males that are usually not from the colony which ensures genetic diversity.

The penis valve contains sharp teeth, which latch onto a thick, soft cuticular layer in the female.

It has been proposed that washing has a hygienic value, keeping the nest area clean, staving off disease and disorder.

It is thought that here, the washing behavior has no hygienic value and instead may be a displacement activity, a sign that the ants are deliberating whether or not to exit the nest.

A single seed colony can populate a large office block, almost to the exclusion of all other insect pests, in less than six months.

Over a period of weeks the IGR prevents the production of worker ants and sterilizes the queen.