The common varieties of ants found in the British Isles are garden insects which pose no threat to public health. They are generally beneficial to the gardener in that they break down the soil, and destroy a variety of unwanted grubs and aphids. There may be occasions however, when worker ants foraging of food gain access to the house and become a nuisance.

VARIETIES

The two common varieties of ant found in Great Britain are the red garden ant (myrmica rubra) and the black garden ant (Lasius Niger). The red ant will not generally be found in domestic dwellings and although it does have a minor sting, it is of no public health significance.

The black ant is more common, and more frequently infests houses when foraging for food. It is the species which generates the 'flying ant'.

LIFECYCLE

The mating season for the black ant is during July and August. At this time, fertile male and female ants emerge from the nest and take to the air as 'flying ants'. During these flights mating takes place.

Shortly after mating the males die, and the females shed their wings and dig a cell in the ground where they spend the winter. The queen emerges in Spring to lay her eggs, which hatch in 3 to 4 weeks and emerge as worker ants some 3 to 4 weeks later. At this stage the worker ants take over responsibility for feeding and building up the colony and will travel considerable distances in the search for food. Eventually the point is reached where the mature male and female ants are ready to leave the nest and take to the air once again for the mating ritual.

NUISANCE CAUSED BY ANTS

The only ant likely to enter the house is the black ant, which does not possess a sting, and is not implicated as a carrier of disease. However, the presence of ants can be irritating and disturbing, particularly when workers are seeking food or when swarms of winged ants gain access to a house. 

CONTROL OF ANTS

Ants in the garden do not constitute a danger, and there should be no need to treat them unless they are gaining access to the house.

If it proves necessary to treat an ant infestation, in the majority of cases, the householder should be able to deal with the problem themselves.

The Council can provide a treatment service for ants if you do not feel confident to carry one out yourself. This is a chargeable service, however, DIY treatment using proprietary brands of insecticide available from chemists, hardware stores and garden centres is inexpensive and if you follow a few simple rules, effective:

1. Ensure that the insecticide chosen is effective against ants.

2. Take care in handling all insecticides and follow the manufacturer's instructions closely.

3. For a treatment to be properly effective it is necessary to destroy the nest. Rather than spray individuals follow the stream of ants until the nest is located and concentrate your insecticide at this point.

4. If the nest cannot be located then it is still possible to destroy the ants with an ant killing bait. This should be placed at the point where the ants are gaining access to the house. They can then pick up the poison on their travels to and from the nest, and return it to the nest to share with others. After a few days numbers should reduce, although it may take a couple of weeks for the treatment to be fully effective. Obviously the ants need to be able to take the poisoned bait back to the nest, and the temptation to kill them on sight must be resisted