Trachymyrmex septentrionalis
Northern Fungus-Gardening Ant
Photo: "Northern Fungus Farming Ant - Trachymyrmex septentrionalis" by Christina Butler, via Wikimedia Commons, licensed under CC BY 2.0.
🐜 At a glance
Origin: Eastern USA; sandy pine barrens and open woodland
Fungus chamber: 22–25°C; never above about 28°C; never heat the nest directly (condensation). Warm the room or an outer box to 22–25°C
Outworld temperature: 18°C night, up to 28°C day; by day like the fungus chamber or a degree or two cooler
Humidity: Fungus chamber 80–90%; outworld about 50%, waste area 30–40%
Winter: Natural winter rest; about 8 weeks at 8–10°C only in a hibernation unit
Moving in: Straight into the setup; after up to 5 hours unopened; colony with fungus only
Size: Queen 5–7 mm; workers 3–4.5 mm, one size, bumpy
Colony: One queen; A few hundred to a few thousand ants
📖 About this species
The world's most northern fungus-growing ant, feeding its fungus garden with dry plant bits, flower parts and caterpillar droppings. A North American ant, not sold by Best Ants UK and possibly illegal or impossible to import to the UK.
🍯 Feeding
Fungus food, every day: oak catkins (fresh, or frozen and thawed), fresh tender shoots and small flower buds, fresh pesticide-free rose petals and soft leaves such as bramble and oak
Snacks only: oat flakes, polenta and dried petals, now and then in small amounts; leftovers out after 2 days
Carbohydrates: a tiny drop of Ant Honey or Ant Nectar now and then; no protein jelly or insects needed
A little at a time on tin foil or a feeding dish in the outworld; remove anything soggy or mouldy at once. Pesticide-free only
💧 Watering the nest
Distilled or purified water only, never tap, rain or mineral water, even boiled.
Pipette a few drops into the damp part of the fungus chamber, away from the fungus, whenever the meter drops below 80%; never drip on the fungus, never puddles. Check every day.
Never water the outworld (about 50%); keep the waste area dry (30–40%).
🏠 Setting up the ant farm
No Best Ants UK ant farm for fungus growers: humid fungus chamber with a digital meter, ventilated foraging area, dry waste area emptied weekly
Arrives in a fungus container (sometimes the fungus separately): unopened up to 5 hours, then straight into the setup
Escape risk: small, good climbers. PTFE Fluon band on the top inner edge of the outworld lid, reapplied every 2–4 weeks
💡 Good to know
North American ant: not sold by Best Ants UK, and possibly illegal or impossible to import to the UK. We never encourage importing ants
Not a true leafcutter: feeds its fungus on catkins, buds, petals and soft leaves. Healthy fungus is white and spongy; yellow = too wet, shrinking = too dry
Never release it. Can't keep it? See our ant adoption page
⭐ Golden rules | Never break these
🚫 Never put ants in a fridge, shed or garage, and never expose them to abrupt temperature changes.
🚫 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 release ants into the wild. If you can no longer keep a colony, visit our ants adoption page and ask us whether we can adopt it.
🛒 Recommended for this species
📚 These care notes cover the essentials only. Please read the full ant farm setup guide and our Trachymyrmex septentrionalis 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.