Lasius niger (black garden ant)

Introduction to Lasius niger

Lasius niger is one of Europe’s most common ant species. It nests in many different environments and objects, such as stubs, meadows or pastures, beneath rocks, crevasses or in your regular lawn. They often build their nests near plants on which they tend to aphids.
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Lasius niger queen with workers and brood. Photo: Lennart Tange.

Appearance of Lasius niger

Worker: Length: 2,0-5,0 millimeters. Dark brown/black with greyish tones. The thorax is lighter than the rest of the body. Legs and antennas (including the first long antenna segment by the head and tibia*) is generously covered with straight protruding hairs. Thorax, legs, mandibles and antennas are slightly lighter than the rest of the body and has a subtle yellow tone to them.

Queen: Length: 7,0-10,0 millimeters. Brown shaded black color. The first long antenna segment by the head and tibia(*) is generously covered in straight protruding hairs. The head is always slenderer than the large thorax. Wings are transparent, but ridden of after the nuptial flights.

Male: Length: 3,5-5,0 millimeters. Brown shaded black color. The mandibles (jaws) are accompanied by a flat tooth near the pointy end. The amount of hair varies, but they are generally fewer than that of the queen. The males always have hairs on the tibia (*). Wings are transparent.


*) The tibia is the third segment of the leg, from the body. It is the equivalent of the human calves.


Lasius niger is found throughout Europe and parts of North America and Asia (2). It is the Lasius species that settles furthest north, all the way to the northern parts of Finland. It has been found from California to Japan, and from North Africa to Finland.

Nuptial flights

The mating of Lasius niger is performed by winged ants. They fly away and mate with other of their species, and then the queens burrows down in the earth to found their colonies.

These ”nuptial flights” take place somewhere between June and September. The European ants of the species tend to mate during hot summer days in July and August, while their North American siblings prefers the autumn months. It is not uncommon for people to see thousands of black garden ants flying away to mate with each other.

Lasius niger habitat and nests

Being a species that is spread throughout most of the northern hemisphere, Lasius niger is great at adapting. It nests in many different environments and objects such as stubs, under rocks, in crevasses, fields, pastures or lawns. They prefer to nest under stones or by plants, where they tend to aphids. The black garden ants sometimes create mounds with the dirt excavated from the nest. And like the yellow meadow ant, Lasius flavus, they like to nest in tussocks or mounds of dirt. But for most parts, the species is found under rocks, taking advantage of the heat absorbed from the sun. It is one of our most common house ants.

Lasius niger is known for its amazing abilities when it comes to adapting to their surroundings. They are often found in cities where they build their nests in pavements, houses and lawns. A nest usually consists of somewhere between a couple of hundreds to tens of thousand of workers. (3)

ant species lasius niger aphids
Worker tending to aphids while the aphid gives birth (yes, sort of like an ant midwife!). Photo: Lennart Tange


The caste of the ant is important to its lifespan. The workers normally live for 1-2 years (4), while queens are able to reach their 30s (although it is very uncommon). The males die shortly after mating.

Castes and chores

The Lasius niger species only have three castes: worker, queen and male. The tasks of the workers varies depending on their age. Young workers tend to stay inside the nest while older ones go out on more dangerous missions.

Lasius niger – from egg to ant

An egg of Lasius niger develops into an adult ant in 8-9 weeks.


The ants of Lasius niger are known to cooperate with other insects. For example, they are often seen tending to aphids locate don plants near the ant nest. The ants protects the aphids in exchange for food in form of honeydew. Lasius niger has been observed building dirt walls to surround their “cattle” and the plants on which they stroll around (5).


The larvae of the parasitic fly Strongygaster globulas lives as a parasite in the abdomen of the niger queen. Her behaviour is not affected by the larvae, but she will stop laying eggs. When the parasite is fully developed it will leave the queen and pupate. The queen will then tend to the pupae as her own. After the birth of the fly, it will escape from the nest and the queen will be left to die.


Lasius niger is considered an easy ant species to keep at home. It easily adapts to different habitats and can survive tough situations such as variations in humidity and temperature as well as lack of food.

Lasius niger information:

Phylum: Arthopoda

Subphylum: Hexapoda

Order: Hymenoptera

Superfamily: Vespoidea

Family: Formicidae

Subfamily: Formicinae

Tribus: Lasiini

Genus: Lasius

Naming: Lasius niger (Linnaeus, 1758)

Pronunciation: [la’-si-us nij’-er]

Etymology: lasius from lasios (gr.) = haired, hirsute. Niger (lat.) = black

Common name: black garden ant


1. Per Douwes, Johan Abenius, Björn Cederberg, Urban Wahlstedt (2012) Nationalnyckeln “Steklar: Myror-getingar. Hymenoptera: Formicidae-Vespidae” p. 151 (Swedish)

2. John H. Klotz, Urban Ants of North America and Europe: Identification, Biology, and Management p. 39

3. Per Douwes, Johan Abenius, Björn Cederberg, Urban Wahlstedt (2012) Nationalnyckeln “Steklar: Myror-getingar. Hymenoptera: Formicidae-Vespidae” p. 152 (Swedish)

4. Human Ageing Genomic Resources

5. Per Douwes, Johan Abenius, Björn Cederberg, Urban Wahlstedt (2012) Nationalnyckeln “Steklar: Myror-getingar. Hymenoptera: Formicidae-Vespidae” p. 152 (Swedish)

Further reading

Black garden ant – Wikipedia

Lasius niger – AntWiki