(Lasius niger)
Black Ant


Temperate species living in soil or in association with dwellings. Form nests in gardens, under paving stones, in foundations or occasionally within buildings. One queen per nest. Workers very active foraging on wide range of foods including sweet substances, seeds, insects and aphid secretions 'honey dew'. Nests may survive for many years but young queens leaving the nest as 'flying ants' start new ones each year.


Egg - larva - pupa - adult. Eggs - laid by queen. Larvae - legless grubs fed by workers, full grown in about 3 weeks. Pupae - known (incorrectly) as 'ant eggs' develop in 2 weeks, guarded by workers. Adults - workers dark brown/black, 3-5mm long. Queens winged at first, 12mm, live for several years.


Foraging workers are a nuisance but not normally a health risk. They guard aphids that damage garden plants. Sexual forms, 'flying ants' may emerge in large numbers close to or inside houses.


Good hygiene standards may prevent infestation. Application of residual insecticide to flooring, walls, building perimeter, cracks and crevices. It is important to locate external nest and treat accordingly. Only to be undertaken by qualified technicians.

Interesting facts

The common Black Ant's have no sting, but they can squirt a spray of formic acid. Some birds put ants in their feathers because the ants squirt formic acid which gets rid of parasites. Ants have the largest brain of any insect. The combined brain cells of a colony of ants have about the same number of brain cells as a human.