Common Black Ant (Lasius Niger)

The most common ant in Britain is the black garden ant otherwise known as the Common Black Ant which prefers a diet of sweet food. We usually see them in our gardens, under patio’s, around the walls, underneath stones, pavement, buildings and sometimes in our kitchen.

The worker garden ants are dark brown or black in colour and about 3-5mm long. The black garden ant queen is around 15mm long and mid brown in colour.One foraging worker ant is able to communicate to her co-workers about a possible meal, shortly after a vast number of worker ants will be invading the food source. This can become a nuisance.


Egg>Lava>Pupa>Adult. Every nest has only one queen and all the eggs are laid by her. The nest may survive for many years, but young queens and matured males leave the nest as “flying ants" in order to mate and start their own colony. Mating of black ants takes place during warm summer days. After mating the male dies and the newly fertilised queens will create a cell for her new colony. The newly fertilised females will lay her first set of eggs in late spring which takes about three to four weeks for hatching. When hatched, the ant larvae are white and legless; the female feeds them with nourishing secretions from her salivary glands. It takes about 3 weeks in order for full grown larvae to pupate. The pupa will develop in 2 weeks into a full grown ant. This first generation of worker ants will take on their duties of foraging for food such as dead insects, seeds, nectar and sugary substance etc. The queen spends all her time in the nest laying eggs and tending to her young. The workers are also responsible for rearing the young or larvae and keeping the nest clean, removing any dead ants or debris.


Common black ants are very active at all times of the day in search of food. When ant colonies are formed in close proximity, one female will assume dominance and will kill the other females to take over her colony. They will travel a considerable distance in search of a suitable food supply marking their trail along the way and communicating with other ants by tapping them with their antennae. Outdoors, worker ants will excavate the soil in order to make it a suitable home for them to breed and live.

Potential harm:

The common black ant is not known to transmit any serious diseases. They can be a problem for gardeners as they will farm aphids (small plant feeding insect) for the honeydew (sugar rich substance); they then carry them into their nest and carry them back out again when necessary. Black garden ants will also eat fruits. Since they are likely to crawl on unpleasant materials, they can contaminate food stuff especially sweet foods.

Prompt Pest Services Control:

Insecticide and baiting formulation can be used for controlling common black ants. Effective ant control indoors involves proofing the area to ensure all possible entry areas are sealed. Treatment will be carried out using professional control materials (such as residual sprays and gel baits). External ant control will be carried out using the same professional control materials but contact dust treatment may also be used.