Ants are the 3rd pest problem in the country. Ant control can be difficult, but there are some things you should know about how ants’ behavior can lead to big headaches for you and your home.

Black garden ant: Facts, Identification & Control

Argentine Ant


Black Garden Ant

Lasius niger


Queen phenotype 7–9 mm long, colour black
Worker phenotype 3–5 mm long, colour dark brown almost black
Nest building Nests underground, commonly under stones, but also in rotten wood Nutrition Nectar, small insects, seeds, will farm aphids


• Foraging worker ants follow well–defined trails around food sources. Sweet foods are preferred but high protein foods will also be taken.
• Swarming characteristics – mating between queens and fertile males takes place on the wing mid to late summer. Males perish after mating.
• Nest locations – often outdoors in soil and below paving slabs on the sunny side of buildings. Nest locations can be identified by the presence of finely powdered soil around nest exit holes.

As pests:

In the garden

This type of ant is a problem for some gardeners. They will farm aphids for the honeydew they excrete by bringing them inside the nest and bringing them back out again when necessary.
The ants will also eat ripe fruits, especially fruits like strawberries that lack a thick protective skin. Often they can be found on discarded chewing gum. Lasius niger also feed on insects and spiders, and other small invertebrates.

In the home

Black garden ants often explore their surroundings quite extensively during early summer months in an effort to increase the food supply to their queen and her young, and also as a way of testing new ground in preparation for the nests' summer flight. In some cases, these explorations lead to a burrowing through mortar and brick.

Pest control:

Control involves application of insecticides in various forms including dusts and liquids. The dusts are injected directly into galleries and voids where the ants are living.
The liquids are applied in areas where foraging ants are likely to pick the material up and spread the poison to the colony upon returning.

Argentine ants