Pharaoh ants are tiny, pale ants that are most often associated with warm buildings. In Britain, they may be found in places such as blocks of flats, hotels, hospitals and food premises.
They can be difficult to identify because they are much smaller and paler than the garden ants people commonly see outdoors. Other small ant species can look similar, so it is best to get a reliable identification before deciding what to do.
What are Pharaoh ants?
The Pharaoh ant is a tropical ant species. In cooler climates, colonies generally depend on the warmth and shelter of buildings.
Unlike many familiar garden ants, Pharaoh ants can establish several connected nesting sites within one building. A colony can also contain multiple queens, which helps it persist and spread.
How to recognise them
Worker Pharaoh ants are very small and usually yellow to light brown. They may follow narrow trails around kitchens, bathrooms, warm equipment and other areas where they can find food or moisture.
Their size and colouring can make identification difficult. A photograph may help, but a close inspection may be needed to distinguish them from other small ants.
Where do Pharaoh ants live?
Nests are often hidden in warm, protected spaces within a building. Possible locations include wall voids, gaps around pipes, service routes, cupboards and equipment.
Workers may travel between rooms while looking for food and water. In a larger building, activity in one area may be connected to nesting sites elsewhere.
Colony growth and spread
Pharaoh ant colonies can contain several queens and occupy more than one nest site. New nesting groups can form through a process called budding. Workers move brood, and sometimes queens, to another location where a new nest can develop.
Budding can happen as a colony expands. Disturbance and some insecticide sprays may also encourage ants to scatter and establish new nesting sites. That is why it is important to identify the species before applying treatment.
Life cycle
Pharaoh ants develop through four stages: egg, larva, pupa and adult. The queen lays eggs, workers care for the developing young, and the adults form the colony’s workforce and reproductive group.
The time taken to develop depends on conditions, especially warmth and access to food. Because colonies can have multiple queens and several nesting sites, seeing fewer ants in one place does not necessarily mean the wider activity has ended.
Why are Pharaoh ants a concern?
Pharaoh ants can forage through different parts of a building, which can create hygiene concerns in food handling and healthcare environments. Their presence does not, by itself, mean that a particular surface or item has been contaminated.
They can also be difficult to manage because nests may be hidden and spread across several locations. Misidentification or poorly chosen treatment can make the problem harder to assess.
What should I do if I find them?
Avoid using household insecticide sprays or dusts until the ants have been identified. Some treatments may disturb the colony and encourage it to spread to other areas.
Note where you have seen the ants and take a clear photograph if possible. In blocks of flats or larger buildings, tell the building manager or property manager, as activity may involve more than one room or property.
How Guardian can help
We’ll assess the ant activity and advise on the most sensible next step. The right approach depends on confirming the species, understanding where activity is occurring and considering the type of building.
If you are unsure what you have found, tell us where you have seen the ants and whether they are appearing in more than one area. A photograph may help with an initial assessment, but it may not confirm the species.
