Pest control: pharoahs ants

Pharaoh's ants (Monomorium pharaonis), pose a health risk because they can infect foodstuffs with a range of diseases such as food poisoning, dysentery and typhoid. In hospitals and care homes they have been known to invade surgical dressings and may transfer infection from one patient to another. Apart from disease carrying they also render food inedible by transferring dirt and filth from their bodies to both food and food preparation surfaces.

Pharaoh's ants are yellow-brown colour and much smaller than the common black or garden ant, being generally less than 2 mm in length. They are normally found living in colonies indoors and like warm damp environments. However, they can occasionally be found in drains or outside ducts, but again these areas must be warm enough for them to happily live and breed.  In  these conditions they will breed prolifically and expand to form new colonies which can contain many thousands of ants, when the original one is under threat.

A queen ant can lay up to 350 eggs each week.  These will hatch after 1 week and develop into mature   adults within a month, so infestations can rapidly grow in size, unless effective treatment is applied. Worker ants will scavenge widely in search of food and will often be seen moving in long chains across work  surfaces, kitchen fittings and in food cupboards. Their mouthparts are strong enough to chew through packaging and plastics.


The Service Provided

The Council carries out Pharaoh Ant Treatments in both Domestic and Commercial properties.

The treatment consists of applying hormone bait to areas frequented by the ants. The hormone works by stopping the ants from breeding and juvenile ants from developing into breeding adults, so the colony naturally dies off.  The hormone only affects the ants.  The treatment will continue to work for up to 2  months, therefore it must not be cleaned away until after all the ants have died off. A follow up treatment is carried out 4 to 6 weeks after the first treatment to check the baits. It is usual to notice a reduction in the number of ants within 28 days but it may take longer for all the insects to disappear, because eggs will continue to hatch. Occasionally during treatment one or two larger ants may be seen. This does not mean they are thriving on the hormone baits, only that the number of worker ants has reduced to such an extent that the larger queen ants are having to leave the nests to forage for food. The treatment is very effective but there are rare occasions when it does not completely work, if ants are still present 4 weeks after the final treatment the Council will carry out a further treatment.



The Council carries out Pharaoh's ant treatments in both domestic and commercial properties. However the Council is not legally obliged to provide this service and therefore has to make a charge to its customers.


Safety Information

The insecticides used by the Council are the safest available and do not pose any risk to people or pets.

Should you use the service you will also be given an information sheet on the insecticide used by the pest controller which provides further information.


Contacting the Service

Treatments can be requested by contacting the Pest Control Service. You can also request a service by completing the online form.