How to Care for Monomorium pharaonis | The Pharaoh Ant Guide
Photo: Dominik Maximilián Ramík, via iNaturalist, licensed under CC BY 4.0.
Monomorium pharaonis, the Pharaoh ant, is a tiny, pale yellow-brown ant that has spread to almost every country on Earth. It lives in huge colonies with many queens, and in cool countries it survives only inside heated buildings.
Its society is remarkable, but it is also one of the best-known pest ants in the world. This guide explains Monomorium pharaonis care honestly, and above all how to stop a single worker or queen from getting out.
Monomorium pharaonis is a tropical tramp ant, and Best Ants UK does not sell it. Importing it may be illegal or impossible, and we never encourage importing ants or collecting pest ants from buildings. This guide is for very experienced keepers and the curious.
We have kept ants since 1997, and these are the care rules we use for our own colonies every day.
👉 In a hurry? Download our free Monomorium pharaonis care sheet (PDF), open the Monomorium pharaonis care sheet page or explore all our free ant care sheets.
Monomorium pharaonis at a Glance
Also known as: the Pharaoh ant or Pharaoh's ant
Origin: uncertain, probably tropical Asia or Africa; now found worldwide, indoors in cool countries
Sold by Best Ants UK: no, it is a tropical tramp ant and a well-known pest
Keeping level: Advanced (very high escape risk and pest status)
Queen: about 3.5 to 5mm, dark reddish-brown
Workers: about 1.5 to 2.5mm, all one size, pale yellow to light brown with a darker tip to the gaster
Colony: many queens (often dozens or more), thousands of workers, spread over several nests
Nest temperature: 26 to 30°C all year, best at around 28°C
Nest humidity: 60 to 70%
Workers before moving into a nest: 50+
Winter: no hibernation, keep warm all year
Escape risk: extremely high, so a fresh PTFE barrier and a tight lid are a must
A Pest Ant: Please Read This First
Pharaoh ants are widespread in Britain, but only indoors. They are found in hospitals, prisons, blocks of flats and homes, wherever the heating stays on. They can get into food and even sterile dressings, and they may carry germs.
A colony has many queens and splits easily. A few workers carrying a little brood can start a new nest, and a whole infestation can grow from one small escape. Infestations are hard to clear, even for professionals.
So think very carefully before keeping this species. You need a perfectly sealed ant farm, a fresh PTFE barrier, a lid that is always closed and the time to check everything every week. If in doubt, choose a UK native instead.
Meet the Pharaoh Ant
The Pharaoh ant got its name because early naturalists thought it came from Egypt. Its real home is still uncertain, but it is a warm-climate ant that has travelled the world with people, food and goods.
Indoors it nests in hidden, warm spaces: wall cavities, under floors, behind skirting boards, in furniture and near hot pipes. The workers forage in long trails and love sweet, fatty and protein-rich foods.
There are no mating flights. The winged males can't really fly, and young queens pair with males inside the nest, then lose their wings. Each queen lives only a few months to about a year, but the colony raises new queens all the time.
Colonies grow by budding: a group of workers walks off with brood, and sometimes queens, to start a new nest close by. Workers can even raise new queens from brood they carry, which is why these ants spread so easily.
When Your Ants Arrive
The most important step: leave the parcel completely unopened, exactly as it arrived, at room temperature for 5 hours. The ants must adjust to your home's temperature slowly, because abrupt temperature changes make ants seriously unwell.
After the 5 hours, check the queens are safe and sound. Then leave the colony in its original packaging, with the test tube still in its tin foil and wrapping.
Put it somewhere quiet and still, away from daily household activity. Normal daylight is fine, but never direct sunlight.
Give the colony 4 to 5 days of complete rest, with no food. A good supplier feeds the ants before dispatch. Use this time to set up and water the nest. 👉 Our step-by-step ant farm setup guide shows you exactly how.
Still workers or a motionless queen after delivery are almost always delivery stress. Look at the antennae: moving antennae mean the ants are fine. Almost all recover within 4 to 5 days.
Life in the Test Tube
Pharaoh ant workers are among the smallest ants kept, so the colony must grow big in its test tube first. Keep it there until it has at least 50 workers. Moved earlier, the workers scatter in the bigger space and the colony can fail.
Colonies start as a group of queens with workers, not a lone queen. If you ever have a queen on her own, give her a tiny drop of protein jelly once a week, about half a grain of rice, on a small flat piece of tin foil inside the tube, next to the dry cotton stopper.
In our experience a fed queen lays more and the colony does far better. Keep the tube wrapped in its foil and disturb it as little as possible.
In real warmth this species breeds non-stop. At about 27°C, brood takes roughly 5 to 6 weeks from egg to adult, and with many queens laying, numbers climb fast.
Moving Into the Ant Farm
When the colony is ready, connect the test tube to the nest with the delivery tin foil still on. Leave it like that for 14 days.
Then slide the foil back about 1mm every day until the tube is fully exposed to daylight. If the ants haven't moved 2 days later, wrap the foil back on, wait another fortnight and repeat. Moving in can take from a couple of days to 6 months.
Once the colony has moved, leave the old test tube connected for at least another 14 days, as ants sometimes leave brood behind.
The red filter and black cover stay on the nest all the time. You can lift the black cover once a day for 2 to 3 minutes, ideally at night, and take the red filter off once a week for 2 to 3 minutes. Take colony photos once a month at most.
The Best Ant Farm for Pharaoh Ants
Pharaoh ant workers fit through gaps you can hardly see, and they can chew soft materials such as rubber and cotton. Their home must be well made and escape-proof, and you should check its connections and stoppers regularly.
For tiny species we recommend the A7 Plus ant farm kit only (you will find the link at the end of this guide). Its small nest suits tiny workers, and its pre-installed digital meter shows nest temperature and humidity at a glance.
Place the ant farm in normal daylight, never direct sunlight. Avoid windows, radiators and heaters, vibrating surfaces, speakers and TVs, and above all the kitchen: strong smells upset the ants, and escaped Pharaoh ants head straight for food.
Temperature and Heating
Pharaoh ants need real tropical warmth. Keep the nest at 26 to 30°C all year. Kept cool, the colony struggles and can collapse.
Almost every UK home is cooler than that. 👉 The Advanced Heating System Small 4W holds a steady warm spot with its digital thermostat. Set it to 28°C.
The heat mat goes under one quarter of the nest only, on the side opposite the watering area, so the ants can choose their spot. Never heat the whole nest.
Warm the outworld too, because a big gap between nest and outworld confuses the ants. Aim for at least 20°C overnight, up to 28°C by day, ideally matching the nest or a degree or two cooler.
Water and Humidity
Keep the nest humidity at 60 to 70%. Pharaoh ants don't like a soaking wet nest, and very high humidity can kill them. Use distilled or purified water only, never tap water, rainwater or bottled mineral water, even boiled: they cause mould and fungus.
Water the nest with the pipette provided. Pour slowly, a few drops at a time, through the watering hole. Stop as soon as 1 or 2 drops appear inside the nest. That is how you know it is done correctly.
Water about once a week. A heated nest dries out faster, so check the meter often and water as soon as the nest humidity drops below 60%.
Never water the outworld. Keep it dry, at about 50% humidity, like an average UK home. A watering test tube in the outworld gives the workers a safe drink.
Feeding Your Pharaoh Ants
Pharaoh ants love both sweet and protein-rich foods. Feed twice a week, in small amounts, in the outworld only. Remove leftovers after 2 days to stop mould.
🍯 For energy, give our 👉 organic ant honey or 👉 Ant Nectar, which has even more carbohydrates than honey. Both are far better than sugar water or home-made mixes. Offer tiny drops, as such small workers easily get stuck in a big one.
🥩 For the queens and brood, give 👉 Protein Jelly or 👉 Cricket Mash. Keep protein jelly in the fridge at all times. A colony raising lots of brood needs plenty of protein.
Serve food on a small piece of tin foil or in a 👉 small feeding dish, so leftovers are easy to lift out.
Live food, such as crickets or locusts, is only for big, established colonies, never small ones. Always scald it first: wearing gloves, hold it with tweezers in just-boiled water (above 90°C, no longer bubbling) for 10 to 15 seconds.
Then cut it in half only, and serve it in the outworld.
Keep Mites Out of Your Colony
Blood-sucking mites are one of the biggest dangers for any ant colony, and they are not rare. They often arrive with bird seed from local shops and off-licences, dried mealworms (useless as ant food), and live food from pet shops or online, where about half carries mites.
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 queens with a magnifying glass. Tiny white or reddish specks on their joints and legs, together with ants dying fast, are a warning sign of blood-sucking mites.
Stopping Escapes
With Pharaoh ants, escape-proofing matters more than anything else. 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 up to about 100 ants, reapply it roughly every 4 weeks. Once the colony reaches 300 to 500 ants or more, which happens quickly with this species, reapply it about every 2 weeks.
Never shake the bottle, because it foams. Roll it gently in your hands instead.
Keep the outworld lid closed at all times, and check every tube, stopper and connection each week. Workers this small use gaps you can barely see.
For extra safety, many keepers of tramp ants stand the whole ant farm inside a larger, smooth-sided plastic box with its own PTFE band. Any escapee is then caught before it reaches your home.
If ants ever do escape, never spray them. Sprays make Pharaoh ants scatter and bud into many new nests. Professional pest controllers use slow-acting baits that the workers carry home.
Winter Care
Monomorium pharaonis is a tropical ant with no winter rest. In the warmth it breeds all year round. Keep the nest at 26 to 30°C right through every UK winter, with the heating system running, and never let the colony get cold.
Never put ants in a fridge, shed or garage, and avoid any abrupt temperature change. Chilling stresses a Pharaoh ant colony and can make it collapse.
If the ants eat less in winter, give a little less, but never guess. If the nest drops to 22 to 26°C, give about half the summer amount, still twice a week, and check your heater.
Can I Release My Pharaoh Ants?
Never. Pharaoh ants can't live outdoors here, but escaped ants settle inside heated buildings and become a serious pest. Never release them, and never let any escape.
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 Monomorium pharaonis good for beginners?
No. Pharaoh ants are among the hardest ants to keep safely. The workers are only about 2mm long, the colony has many queens and escaped ants are a serious building pest. They are for very experienced keepers only. For a first colony, choose a UK native such as Lasius niger.
Can I buy Monomorium pharaonis in the UK?
Best Ants UK does not sell Monomorium pharaonis. It is a tropical tramp ant and one of the best-known indoor pests in Britain, so we don't offer it. We never encourage importing ants.
Why are Pharaoh ants a problem in buildings?
In the UK they live only indoors, in warm, heated buildings such as hospitals and blocks of flats. They are so small they can get into food and even sterile dressings, and they may carry germs. Colonies split easily, so infestations spread.
How many workers before moving Pharaoh ants into a nest?
At least 50 workers. The workers are only about 1.5 to 2.5mm long, so a smaller colony is lost in an ant farm. The same rule applies to a queen on her own.
What temperature do Pharaoh ants need?
Keep the nest at 26 to 30°C all year. Most UK homes are much cooler, so use an Advanced Heating System set to 28°C under one quarter of the nest. Never let the colony get cold.
Do Pharaoh ants hibernate?
No. This tropical ant has no winter rest. In the warmth it breeds all year round. Keep the heating on right through the winter and never put the ants in a fridge, shed or garage.
What if my Pharaoh ants escape?
Never spray them. Sprays make Pharaoh ants split into many new nests and spread further. Professional pest controllers use slow-acting baits. Strong escape-proofing from day one is the only real protection.
Ready to Keep Ants the Safe Way?
👉 Whatever species you keep, start with the A7 Plus ant farm kit. Its small nest suits tiny workers, its pre-installed digital meter shows temperature and humidity at a glance, and if you already have your ants, choose its Nest + Outworld option.
