How to Care for Atta cephalotes | The Giant Leafcutter Ant Guide
Updated: 3 days ago
Long lines of ants carrying green leaf pieces over their heads: that is Atta cephalotes, the giant leafcutter ant of the American rainforest. The ants don't eat the leaves. They use them to grow a fungus garden, and the fungus feeds the whole colony.
Few sights in ant keeping beat a busy leafcutter trail, from tiny gardeners to huge soldiers. This guide explains Atta cephalotes care step by step, from the day a colony arrives to a thriving fungus farm.
We have kept ants since 1997. Leafcutters are an expert species, so read this guide from A to Z before you start.
👉 In a hurry? Download our free Atta cephalotes care sheet (PDF) or open the Atta cephalotes care sheet page for the key facts at a glance.
Atta cephalotes at a Glance
Origin: tropical rainforests of Central and South America
Keeping level: Expert
Queen: about 30mm, reddish brown and hairy
Workers: 3 to 16mm, glossy reddish brown to amber, with spines
Soldiers: 18 to 23mm, with huge heads and hairy cheeks
Colony: one queen; in the wild, millions of ants
Main food: fresh leaves for the fungus garden
Fungus chamber temperature: 23 to 26°C all year
Fungus chamber humidity: 80 to 90%
Waste area: dry, about 30 to 40% humidity
Moving in: straight into the setup after up to 5 hours of settling; always a whole colony with its fungus, never a lone queen
Winter: no hibernation, warm all year
Meet the Giant Leafcutter Ant
In the wild, Atta cephalotes lives in the tropical rainforests of Central and South America. It builds huge underground nests with many chambers, and a mature colony can hold 5 to 8 million ants.
The workers come in many sizes, and each size has its own job. The smallest look after the fungus and the brood (the eggs, larvae and pupae). Medium workers cut and carry leaves. The giant soldiers guard the trails.
Watch the leaf pieces on the trail. Tiny workers often ride on top of them like bodyguards, chasing away parasitic flies that try to attack the carriers.
The fungus is the heart of the colony. The ants chew the leaves into a pulp and grow the fungus on it. The fungus forms small food bodies that the workers harvest for the queen and brood.
New queens fly out at the start of the rainy season. Each one carries a small piece of fungus from her mother's nest, starts a new garden with it, and can live for about 15 years.
When Your Ants Arrive
Leafcutter colonies arrive in a fungus container, with the ants and their fungus garden together. Sometimes the ants come in a small container of their own and the fungus is supplied separately.
The most important step: leave the parcel completely unopened, exactly as it arrived, at room temperature for up to 5 hours. Leafcutters need this time to settle, because abrupt temperature changes make ants seriously unwell.
After that, open the parcel, check the queen is safe and sound, and transfer the colony into its setup straight away. Leafcutters must not wait in their travel container, so have the setup warm, humid and ready before the parcel arrives.
If the fungus came in its own container, place it gently in the fungus chamber or connect its container to it, then let the ants in right next to their garden. Move the fungus as little as possible, and never shake, tip or squeeze it.
🍃 Offer fresh, lightly misted leaves as soon as the ants are in their setup. The fungus garden needs them to keep growing.
Still workers or a motionless queen after delivery are almost always delivery stress. Look at the queen's antennae: moving antennae mean she is fine. Almost all recover within 4 to 5 days, and a big leafcutter queen can take a little longer.
Don't worry if part of the fungus garden looks damaged. Losing up to a third of the fungus in transit is normal. With the right warmth, humidity and fresh leaves, the ants rebuild it.
Always a Colony, Never a Lone Queen
Leafcutters are only kept as a colony: the queen, her workers and their fungus garden, together. A queen on her own can't tend the fungus, and the fungus is the colony's only food.
Once the colony is in, leave the fungus garden to the ants. They move and rebuild it themselves, piece by piece. All you do is keep the conditions right and the leaves coming.
The Right Setup for Atta cephalotes
Best Ants UK doesn't offer an ant farm for leafcutters. Experienced keepers build a setup with three connected areas: a warm, humid fungus chamber, a foraging area (outworld) where you give the leaves, and a separate dry waste area.
The fungus chamber needs a digital humidity and temperature meter, because with leafcutters the humidity must be right every single day. Plan for more room in all three areas as the colony grows.
The ants carry used leaf pulp, old fungus and dead workers to the waste area. Empty it gently about once a week with long tweezers, before it smells or goes mouldy, and never put anything from it back into the fungus chamber.
Keep the fungus chamber dark. Lift its cover only briefly, about once a day for 2 to 3 minutes, ideally at night, and take colony photos once a month at most.
Place the setup in normal daylight, never direct sunlight. Avoid windows, radiators and heaters, vibrating surfaces, speakers and TVs, busy walkways and rooms with strong smells such as the kitchen.
Temperature and Heating
Keep the fungus chamber at 23 to 26°C, all year round. Most UK homes are far cooler than a rainforest, especially from autumn to spring, so leafcutters can't thrive without gentle heating.
👉 We recommend the Advanced Heating System Small 4W. Its digital thermostat holds a steady warm spot. Set it to 25°C and put it under one quarter of the fungus chamber, on the side away from where you add water, so the ants can choose their spot.
Keep the outworld at 21 to 28°C. By day it should ideally match the fungus chamber or be a degree or two cooler. If the fungus chamber is heated, warm the outworld too. Never let the fungus chamber go above about 28°C: an overheated, dry fungus garden dies.
Water and Humidity
Humidity is everything for leafcutters. Keep the fungus chamber at 80 to 90%. If the fungus dries out, the colony starves. Use distilled or purified water only. Never use tap water, rainwater or bottled mineral water, even boiled: they cause mould.
Add water with a pipette, a few drops at a time, to the damp part of the fungus chamber, away from the fungus. Never let water drip onto the fungus itself, and never let it stand in puddles.
With a digital meter in the fungus chamber, water whenever the fungus chamber drops below 80%. Leafcutters need far more humidity than most ants, so check the meter every day, not just once a week.
Never water the outworld. Keep it at about 50% humidity, and keep the waste area dry, at about 30 to 40%. The only water in the outworld is a fine mist on the leaves before you give them.
Feeding Your Leafcutter Ants
🍃 Fresh leaves are the main food, every day. The ants cut them up and feed them to their fungus. Bramble (blackberry), raspberry, rose, box, elder, lime (linden) tree and oak leaves all work well. Mist them lightly before feeding, never soak them.
Only use leaves free from pesticides and road dirt. Never use staghorn sumac: it is toxic to the fungus. Remove old, dried-out leaves after 2 days, before they go mouldy.
🍎 Small pieces of apple, orange, banana or grape and rose-family flowers make welcome extras. Put fruit on a piece of tin foil or in a 👉 small feeding dish in the outworld.
Our dried Dandelion Leaves, Rose Petals and Blue Mallow Flowers are safe for the fungus too. Fresh leaves should still be the main food, so alternate them with fresh leaves every other day. Oat flakes are for emergencies only, when you run out of leaves.
🍯 A tiny drop of our 👉 organic ant honey or 👉 Ant Nectar on tin foil now and then gives the workers extra energy. Both are far better than sugar water or home-made mixes.
🥩 Leafcutters don't need protein jelly or insects. The fungus makes the protein the queen and brood need.
In a UK winter, finding fresh leaves gets harder. Bramble often keeps its leaves through a mild winter and box stays green all year, so find a clean, pesticide-free source before the cold months come.
Keep Mites Out of Your Colony
Blood-sucking mites are a real danger for every ant colony, and they are not rare. They often arrive with bird seed from local shops and off-licences, dried mealworms, and live food from pet shops or online, where about half carries mites.
Leafcutters need none of those foods, which helps. Buy ant food only from established, reputable ant-keeping suppliers. At Best Ants UK we clean our foods before dispatch, check every colony twice a month, and check each colony again before it leaves us.
Now and then, look at your queen with a magnifying glass. Tiny white or reddish specks on her joints and legs, together with ants dying fast, are a warning sign of blood-sucking mites.
Stopping Escapes
Leafcutter workers are strong climbers and always exploring. Paint a band of 👉 PTFE Fluon escape barrier around the top inner edge of the outworld lid. The ants slip off it and can't climb out.
PTFE wears off as the ants keep testing the same spots. For a colony of up to about 100 ants, reapply it roughly every 4 weeks. For 300 to 500 ants or more, reapply it about every 2 weeks. Never shake the bottle; roll it gently instead.
Winter Care
Atta cephalotes has no winter rest. Keep the fungus chamber at 23 to 26°C and keep giving fresh leaves all year round.
In the cooler months, the heating system does most of the work. Never put ants in a fridge, shed or garage, and avoid any abrupt temperature change. Cold doesn't kill a colony at once: the ants sicken and die over the following days.
Can I Release My Leafcutter Ants?
No. A colony raised indoors won't survive outside. If you ever can't keep your colony any more, 👉 visit our ant adoption page and let us know. We'll see whether we can take it in.
Frequently Asked Questions | FAQ
Is Atta cephalotes good for beginners?
No. It is an expert species. The fungus garden needs steady warmth, very high humidity and fresh leaves every day, and the colony grows fast. Start with an easier species such as Lasius niger or Messor barbarus, and come back to leafcutters later.
What do Atta cephalotes eat?
The ants feed fresh leaves, flowers and a little fruit to their fungus garden, and the fungus feeds the colony. Bramble, raspberry, rose, box, elder, lime (linden) and oak leaves all work well. They don't need protein jelly or insects.
Can I buy an Atta cephalotes queen on her own?
No. Leafcutters are only kept as a colony: the queen, her workers and their fungus garden. A queen on her own can't look after the fungus, and without it the colony has nothing to eat.
What temperature do Atta cephalotes need?
Keep the fungus chamber at 23 to 26°C all year round, and the outworld at 21 to 28°C. In most UK homes that means an Advanced Heating System under one quarter of the fungus chamber, set to 25°C.
Do Atta cephalotes hibernate?
No. They come from tropical rainforest and never rest for winter. Keep them warm and fed all year, and never let the colony get cold.
How humid should the fungus chamber be?
Keep it at 80 to 90%, using distilled or purified water only. A digital humidity meter in the fungus chamber makes this far easier. If the fungus dries out, the colony starves.
Do Atta cephalotes sting?
No, they have no sting. The big soldiers can give a hard bite with their strong jaws, though, so never handle them and keep the outworld lid closed.
Start Your Own Leafcutter Colony
👉 Find Atta cephalotes colonies in our shop and check availability, then watch your own giant leafcutters build their fungus farm.
Print this guide and keep it next to your leafcutter setup. 👉 Keep the essentials close and explore all our free ant care sheets.
