General information

Common name

Black garden ant

Binomial nomenclature
Lasius niger

Family: Formicidae
Subfamily: Formicinae
Genus: Lasius
Species: Lasius niger

Common in Europe and some parts of North America and Asia. See

Abundant in gardens, streets and parks.

Nests in any soil.

Workers: 3 – 5 mm
Queen: 9 mm
Males: 3,5 – 4,5 mm

Keeping and care

Very easy. Great species for beginners.

Behavior and description
No sting and too small to bite humans. Active and aggressive ants. Dark brown color.

Colony type
Secondary monogynous. It’s possible to found a colony through pleometrosis (multiple queens), but eventually they will fight and one queen will survive. Independent founding. Colony size up to a few thousand. Queen can live up to 20 years.

Queen capture
Capture unwinged queens after nuptial flight. Digging out a colony is not recommended because of the monogynous nature of the colony, making it almost impossible to find the queen.

Nuptial flight
July – August

Test tube setup for small colonies, ytong nests for large colonies, with a foraging area attached. Plaster and sand nests are possible, but less convenient. Plaster will mold and in sand their visibility is decreased.

Nest conditions
This species is not picky. Some humidity is required. Best is to offer a nest where one part has high humidity and one part has lower humidity, so they can choose. Can be kept at room temperature. They tolerate a wide range of temperatures, so heating is not required. Covering the nest to make it dark is recommended to reduce stress, but an uncovered nest will also do. Covering with red foil is to no avail, as Lasius niger can see red light.

Escape prevention
Fluon, talcum powder, paraffin oil. They tend to wipe off the talcum powder after a while.

Yes. A six-month dormancy from October to March is required. As a northern temperate species, Lasius niger needs cold reactivation for a rapid growth in spring, otherwise growth will stagnate. Stop feeding and slowly drop the temperature to 5 degrees Celcius (41 degrees Fahrenheit). Make sure the nest stays humid. During dormancy their metabolism is strongly minimized, so feeding is not required, but moist is. After dormancy, increase the temperature slowly to room temperature to avoid intoxication by built-up toxics due to the reduced metabolism.

Honeydew surrogate, sugar water, insects (e.g. fruit flies, crickets, Blaptica dubia).


Lasius niger
April Nobile / © / CC-BY-SA-3.0
Lasius niger
In the garden
Lasius niger
Queen with workers
Lasius niger
Larvae, pupae and workers

More information

More caresheets

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13 thoughts on “Lasius niger: Caresheet

    1. I’m sorry, I don’t have any experience with that species. If you or anyone else could write a caresheet according to the template above, I wouldn’t mind adding it to the website (with credits of course).

    1. Depends on the temperature in your shed, if it gets below zero your ants will likely die. Around 5 degrees Celsius is acceptable.

  1. Is there some kind of a repellant that I can use to keep these away? I don’t want to kill them, but I’m trying to sell my house and a get a straggler or two that tend to find their way into my kitchen. They like to roam around my sink and on my counters. I’ve lived here for 15 years and I’ve just let them be as they’ve never bothered me, but seeing one crawling on the counter is not a site that turns a home buyer on. Please advise. Thanks!

  2. would it be ok to keep a Lasius niger nest in a conservatory which is very susceptible to the weather when its hot its hot and when its cold its cold in there, (ive not tested the actual temp), plus a dryer in there causes moisture sometimes, i live in the UK.

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