Lasius niger

Black Garden Ant

🐜 At a glance

Origin: 🇬🇧 UK native; found across Europe
Keeping level: Beginner — the perfect first species. No sting, completely harmless
Queen: 8–9mm, black; queens can live for decades — the oldest on record reached almost 29 years
Workers: 3–5mm, black to dark brown
Colony form: Single queen (monogyne)
Nest temperature: 20–26°C — normal UK room temperature, no heating needed
Nest humidity: 75–85%
Workers before moving into a nest: 10+
Winter: Hibernation optional — see below

📖 About this species

Hardy, forgiving and perfectly suited to UK homes, Lasius niger is the best first species for any new keeper. They are naturally calm ants — mostly still unless foraging — so do not worry if your colony looks quiet. From egg to adult worker takes 6 to 8 weeks, and the first workers (nanitics) live only 1 to 3 months: their job is to serve the queen until the second batch hatches.

📦 When your ants arrive

⚠️ MOST IMPORTANT: leave the parcel completely unopened, exactly as it arrived, at room temperature for 5 hours. The ants must adjust to your home’s temperature gradually — abrupt temperature changes make ants seriously unwell.
After the 5 hours, check the queen is safe and sound, then leave the colony in its original packaging (test tube still in its tin foil and wrapping) in a quiet spot — in daylight, never direct sunlight — away from vibration and daily household activity.
😴 Give the colony 4 to 5 days of complete rest. The ants were fed before dispatch and need nothing from you during this time. Assemble and water the nest while you wait.
Still workers or a motionless queen after delivery are almost always delivery stress. Check the antennae: moving antennae means she is fine. Almost all recover within 4 to 5 days (a little longer for bigger queens).
Do not remove the black divider inside the test tube (between the two cotton stoppers) — it keeps the ants safe in transit. It has a hole, and the queen and all workers pass through it without any issue.
👑 A queen on her own: keep her test tube wrapped in its tin foil, undisturbed, and feed her once a week — a tiny drop of protein jelly, about half a grain of rice, on a small flat piece of tin foil placed inside the tube next to the dry cotton stopper. In our experience a fed queen is stronger and her brood develops about 30% faster.

🏠 Moving into the ant farm

Keep the colony in its test tube until it has at least 10 workers. Moved earlier, the workers often abandon the queen in the larger space, which can lead to colony failure. A queen bought on her own, with no workers yet, needs a little longer: she stays in her test tube until she has 15+ workers.
Connect the test tube to the nest with the delivery tin foil still on and leave it for 14 days. Then slide the foil back about 1mm every day until the tube is fully exposed to daylight.
If the ants have not moved in 2 days after the tube is fully exposed, wrap the foil back on, wait another fortnight and repeat the whole process — patience is the key. Moving in happens on the ants’ own time: anywhere from a couple of days to 6 months.
The red filter and black cover stay on the nest at all times — it is pitch dark inside. The black cover can come off once a day for 2 to 3 minutes (ideally at night); the red filter once a week for 2 to 3 minutes.
☀️ Place the ant farm in normal daylight, never direct sunlight (the sun can overheat a nest within minutes). Avoid windows, radiators and heaters, vibrating surfaces, speakers and TVs, strong smells such as the kitchen, and busy walkways. Keep a steady room temperature.

🍯 Feeding

🍯 Sugars for worker energy: our organic ant honey (lab-tested at 81% carbohydrate) or Best Ants UK Ant Nectar (90% dextrose, an even richer energy source) — never sugar water or home-made mixes.
🥩 Protein for the queen and brood: Best Ants UK Protein Jelly or NextSwarm Cricket Mash. Keep protein jelly in the fridge at all times once opened.
Feed twice a week, small amounts, in the outworld only. Remove leftovers after 2 days to prevent mould.
🦗 Live food (mealworms, crickets, locusts) is only for established colonies, never small ones. All bought live food carries tiny mites that can destroy a colony, so always scald it first: hold it with tweezers in just-boiled water (no longer bubbling) for 10 to 15 seconds, then chop it in half and serve on a small tin foil tray.

💧 Watering the nest

💧 Use distilled or purified water only — never tap, rainwater or bottled mineral water, even boiled. They carry minerals and microbes that turn a nest green with mould. A litre of distilled water costs a few pounds and lasts over a year.
Water the nest with the pipette provided: pour slowly, a few drops at a time, through the watering hole, and stop as soon as 1 or 2 drops appear inside the nest — that is how you know it is done correctly. More than that is too much.
Once a week is usually right — slightly more in summer, less in winter. Never water the outworld.

🌡️ Temperature and winter

No heating is needed: Lasius niger thrives at normal UK room temperature all year round.
Hibernation is NOT a must in captivity. At room temperature (17–26°C) the colony simply slows down naturally over winter — development continues at roughly half the summer rate at 20–26°C, and roughly a third at around 15°C. The biological clock cannot be tricked.
❄️ Full hibernation (development stops completely) happens at a steady 10°C from roughly 1 December to the end of March, with fresh water only and no food. If you cannot keep the colony at a steady 10°C, do not hibernate it — leave it at room temperature, where it slows down naturally. Never use a fridge, shed or garage.
Never hibernate a first-year queen, and always cool down and warm up gradually. Sudden cold, or long spells near freezing, can damage the sperm the queen stores from her nuptial flight.
A queen with eggs kept at 20–26°C keeps developing over winter, just slowly — first nanitics in 6 to 12 weeks.

⭐ Golden rules | Never break these

🚫 Never put ants in a fridge, and never expose them to abrupt temperature changes. Cold does not kill a colony instantly — the ants get sick and die over the following days — and prolonged cold near freezing damages the sperm a queen stores from her nuptial flight, so she may never lay fertile eggs again.
🚫 Never use gel ant farms, Ytong or concrete nests, or DIY nests.
🚫 Never use tap, rain or mineral water, even boiled.
🚫 Never move a colony into a nest too early, and never tip or shake ants out of their tube.
🚫 Never disturb the colony with tapping or handling — vibration stresses the queen and she can stop laying or eat her eggs.
☀️ Never keep the farm in the dark: ants need daylight for their circadian rhythm. Daylight yes — direct sunlight never.

🛒 Recommended for this species

📚 These care notes cover the essentials only. Please read the full ant farm setup guide and our Lasius niger care guide from A to Z. Questions? Message us through our contact form and we will be happy to help. 💚

Written and reviewed by the Best Ants UK team, keeping ants since 1997.