Garden and Pharaoh's Ants

Since 31 August 2013 the Council has ceased to offer a pest control service to residents. This information page is a guidance for residents.

Garden Ants

What do they look like?

The worker ant is a large ant 3-5 mm in length and dark brown to black in colour. The Queen is about 12mm long and slightly lighter in colour.

How do I spot them?

  • The black garden ant is the most common and is found in almost all parts of the country.

  • The ant is an active insect and nests outside, in grass, walls and under paving. It enters buildings in search of food.

How do they affect me?

Foraging worker ants cause a nuisance as they travel widely in search for food, usually following well-defined trails and clustering around a food source. Ants may cause considerable nuisance occasionally invading food prepared for human consumption.

How do they live?

Ants live for about two months, but in good conditions a nest can last for years. Garden ants mate in flight when winged males and females swarm between mid July and mid September. Although swarms may be a nuisance they are harmless and nothing can be done to stop a Nuptial Flight.

After mating the male dies and the female loses her wings and buries herself in the soil over winter. In late spring the female lays eggs which hatch into white larvae in 3-4 weeks.

The larvae are fed by the queen and when fully grown pupate forming the well-seen ant eggs. The worker ants which emerge from the pupae feed new larvae and the queen. The entire cycle takes about 2 months to complete and under favourable conditions a nest may persist for several years.

How do I control them?

In many cases where ants are a problem indoors it is because they have either established a nest beneath the foundations or very close to an outside wall and are finding their way into the building.

Boiling water poured on the nest will control the infestation for a short time. Follow this by puffing an insecticidal powder product into the hole. Select a powder product which lists ants on its label.

Other ways to control ants includes applying a contact insecticide, e.g. ant powder, or use a gel placed on, for example, a small piece of glass, which the worker ants feed on and take back to their brood within the nest. If persistent, the gel may eventually destroy the nest. If you decide to use a powder it should be applied to cracks and crevices along and under skirting boards where ants are a problem. A small amount of powder should be applied to the floor and using a small paint brush, dusted into cracks and crevices. To treat inaccessible areas such as under kitchen units a small hole can be drilled in the plinth, which will allow powder to be dusted into these void spaces.

Practical advice

  • It is important to read the label of any container or box before using an insecticidal powder or gel.
  • Do not apply insecticide on the outside walls of properties as the colony may be underneath the foundations. This could stop the ants foraging in the garden and so compound the problem indoors.
  • Ensure that sugary foods are kept in sealed containers and all food spillages are cleared up.
  • Some products on the market are harmful to pets, others are not. It is important that you read the label and follow the instructions taking all the necessary precautions when applying the product.

Pharaoh's ants

What do they look like?

Pharaoh's ants are very small and pale in colour.

How do I spot them?

Nests are found in cracks near to central heating boilers, hot water tanks and ovens. Hospitals and bakeries are the most common premises affected. They are unable to breed outdoors as they need temperatures of at least 18ºC (65ºF) to flourish.

How do they affect me?

They can crawl into sterile packets in hospitals or into food preparation areas and spread germs.

How do they live?

In a typical nest, 50,000 Worker ants will travel along well-defined trails to collect food and water to take back to the nest. There it is used to feed up to 400 egg laying queens and 100,000 young immature stages. There are often several different nests in infested premises.

Colonies spread to new sites by small groups of workers carrying some brood away from the nest. A temporary resting place such as a pile of laundry or cardboard box may be transported to another building and thus start up a new infestation.

How do I control them?

It is very difficult to completely eliminate an infestation using ordinary insecticides. It is essential to get enough poison into the actual colony to destroy the queens and brood, not just kill workers on their travels. It is also vital that all of the colonies in the block are dealt with at the same time or the problem will recur within a few months.


Contact Details