Size: 4mm

Colour: Dark brown – black

Garden Ants usually nest n outdoors in lawns, flower beds, beneath paving flags or at the base of walls.

During summer, winged females (Queens) and males leave the nest on one or two warm afternoons and take flight. Sometimes, during this flight – which lasts for two to three hours – the ants may fly inside buildings. In this event, the problem may be overcome by using a flying insect spray.

Houses are usually invaded by worker ants foraging for food, especially sweet foods. When food is found by one ant, there will soon be others and a trail of worker ants take food back to the nest.

Ant Control

If possible, trace the trail of worker ants to the nest. The openings to the nest can often be recognised by small piles of fine earth being brought up from underground. If the nest can be exposed, pour boiling water into it.

If it is not possible to trace the nest, use an insecticidal dust or spray labelled for the control of crawling insects, to treat outside the building and the ground around. Special attention should be paid to likely entry points such as door frames, air bricks and waste pipes to create an insecticidal barrier.

Pesticides that contain bendiocarb are usually found to be most effective. The same insecticide may be used indoors where ants have been found wandering. Application should form a continuous band around skirtings, taking care not to contaminate food with insecticide.

Alternatively, an ant bait containing Borax may be used which foraging workers take back to the nest. This is effective, but requires persistent application until completely clear.

Suitable insecticides may be purchased at garden centres or chemists. Garden ants do not bite, are not known to carry disease, and are not considered to be a public health hazard.


Whenever insecticides are used, read and follow the instructions on the label carefully.