How to Care for Pogonomyrmex bicolor | The Bicoloured Harvester Ant Guide for Adult Keepers
Updated: 2 days ago
Photo: Jake Nitta, via iNaturalist, licensed under CC BY 4.0.
Pogonomyrmex bicolor, the bicoloured harvester ant, is a desert ant with a two-tone look: a bright rusty red head, thorax and legs, and a dark, almost black gaster (the rear part of the body).
This guide explains Pogonomyrmex bicolor care step by step, from arrival to a thriving nest. It is written for careful adult keepers, because this harvester has a serious sting.
We have kept ants since 1997, and the care rules here are the ones we use every day with our own harvester ants.
👉 In a hurry? Download our free Pogonomyrmex bicolor care sheet (PDF) or open the Pogonomyrmex bicolor care sheet page for the key facts at a glance.
Pogonomyrmex bicolor at a Glance
Origin: the Sonoran Desert of southern Arizona and north-west Mexico
Keeping level: Advanced, for adults only (very painful sting)
Queen: about 9 to 11mm
Workers: about 5 to 8mm (occasionally up to 9.5mm), rusty red with a dark brown to black gaster, no soldier caste
Colony: one queen, a few thousand workers when mature
Main food: seeds
Nest temperature: 26 to 30°C
Nest humidity: 50 to 60%
Workers before moving into a nest: 10 minimum, 15 to 20 recommended
Winter: a 2 to 3 month rest at about 17 to 18°C, never below 15°C
Water: never open water, a watering test tube only
Sold by Best Ants UK: no, it is a North American species
Meet the Bicoloured Harvester Ant
In the wild, Pogonomyrmex bicolor lives in open desert in southern Arizona and the Mexican states of Sonora, Sinaloa and Chihuahua. It nests in bare, gravelly soil between widely spaced shrubs and cacti.
Less is known about this harvester than about its famous cousins. Each nest has one central entrance leading to a main tunnel about 30 to 45cm deep, with side tunnels branching off. Some nests have a low mound, others a ring of soil and pebbles like a small crater.
Each colony has a single queen, and established colonies reach thousands of workers. Seeds are their main food, and the workers forage slowly in neat lines.
Winged queens and males have been found in late July and early August, after the summer rains. After mating, a queen pulls off her wings and seals herself away to raise her first workers on her own body reserves.
When disturbed, the workers often freeze, lift the front of the body, open their jaws wide and wave their antennae. They can hold this threat pose for up to 15 minutes.
Can You Keep Pogonomyrmex bicolor in the UK?
Pogonomyrmex bicolor is a North American ant, and Best Ants UK does not sell it. It may be illegal or impossible to bring into the UK, so please never try to import it, and never buy it from anyone offering to ship it here.
This guide is for keepers who live where the species is native and can keep it legally, and for anyone curious about harvester ants.
If you are in the UK and dream of harvesters, our Messor barbarus is a calm, hardy harvester ant with no sting at all, and much of this guide works for it too.
Watch our Messor barbarus care guide, filmed with our own 19-year-old harvester ant colony:
A Painful Sting | Adults Only
Like its relatives, Pogonomyrmex bicolor has a real sting, and it is very painful. The pain can last for hours, and in some people a sting can cause an allergic reaction. Anyone who reacts badly to a sting should get medical help straight away.
Keep this species for adults only, out of reach of children and pets. Never handle the ants, never put your fingers into the outworld, and use long tweezers for any work inside it.
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 queen is safe and sound. Then leave the colony in its original packaging, with the test tube still in its tin foil and wrapping, somewhere quiet and still, away from daily household activity. Daylight is fine, never direct sunlight.
Give the colony 4 to 5 days of complete rest. The ants were fed before dispatch, so they need nothing from you. Use this time to set up and water the nest. 👉 Our step-by-step ant farm setup guide shows you how.
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 big harvester queens can take a little longer.
Life in the Test Tube
Keep the colony in its test tube until it has at least 10 workers. 15 to 20 is even better. Moved earlier, the workers often abandon the queen in the bigger space, and the colony can fail. The same rule applies to a queen on her own.
A founding queen still needs a little food. Once a week, give her a tiny drop of protein jelly, 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 raises her first workers faster and does far better afterwards. Keep her tube wrapped in its foil and disturb her as little as possible.
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 Pogonomyrmex bicolor
👉 For harvester ants we recommend the Angie ant farm starter kit, our harvester ant farm with a pre-installed digital meter. It shows the nest temperature and humidity at a glance, which matters a lot here, as too much water makes seeds sprout.
The A7 Plus ant farm, also with a pre-installed digital meter, is a great choice too. If you already have your ants, choose its Nest + Outworld option.
Place the ant farm in normal daylight, never direct sunlight. Avoid windows, radiators and heaters, vibrating surfaces, speakers and TVs, and rooms with strong smells such as the kitchen.
Temperature and Heating
Keep the nest at 26 to 30°C. Most UK homes are much cooler than that, so this species cannot thrive without gentle heating.
👉 We recommend the Advanced Heating System Small 4W. Its digital thermostat holds a steady warm spot. Set it to 28°C, the middle of the ideal range.
On a horizontal nest such as Angie or the A7 Plus, the heat mat goes under one quarter of the nest. On a vertical nest, it goes under half. Always put it on the side opposite the watering area, so the ants can choose their spot.
The outworld can cool to about 18°C overnight and warm up to 28°C by day. By day it should ideally match the nest or be a degree or two cooler. If the nest is heated, warm the outworld too.
Water and Humidity
Keep the nest humidity at 50 to 60%. This is a dry-country ant, and too much water makes stored seeds sprout and mould. Use distilled or purified water only. Never use tap water, rainwater or bottled mineral water, even boiled.
Water the nest about once a week with the pipette provided. Pour very slowly, a drop at a time, through the watering hole. With harvesters, be extra careful: no more than 1 drop should leak into the nest.
With a meter, simply water when the nest humidity drops below 50%, a little sooner in summer and later in winter.
Never water the outworld. Keep it dry, at about 50% humidity, like an average UK home.
Harvester ants must never have open water, because they can drown in it. Give them a watering test tube in the outworld, not a water dispenser. Much of the water they need comes from their food.
Feeding Your Harvester Ants
🌾 Seeds are the main food. Give our 👉 harvester ant seed mix. Start with a small pinch and give more as the colony grows and collects it.
Always put the seeds on a piece of tin foil or in a 👉 small feeding dish in the outworld. Never put them straight on the substrate: damp seeds sprout, and sprouted seeds are harmful to the colony.
🥩 Once a week, for example every Monday, give a little 👉 Protein Jelly. The queen and brood need it to grow. Keep protein jelly in the fridge at all times.
🍯 Once a week on another day, for example every Thursday, 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.
Young colonies and lone queens lean more on protein and honey than on seeds. Feed in the outworld only, and remove leftover jelly and honey after 2 days to stop mould.
Keep Mites Out of Your Colony
Blood-sucking mites are one of the biggest dangers for harvester ants, 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 in several ways before dispatch, check every colony twice a month, and check each colony again before it leaves us.
A home freezer won't kill all the mites in seeds, so never rely on it. We freeze our seeds below -60°C in a special freezer before they reach you.
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
With a stinging species, escape-proofing matters even more. 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
In the wild, Pogonomyrmex bicolor slows down in winter. In captivity, give it a winter rest of 2 to 3 months, for example from December to February, at about 17 to 18°C. It does not need a cold hibernation.
Harvesters are sensitive to cold: 15°C is the absolute minimum, and 17°C or above is safe. Switch the heating off for the rest and let the room cool gradually. Never put ants in a fridge, shed or garage, and never move them from a warm room straight into a cold one.
If the room falls below 17°C, switch the heating back on. We never give a queen a winter rest in her first year: keep her at her normal warmth. The colony slows down in winter anyway: its biological clock can't be tricked.
Feed less in winter, but never guess. At 17 to 22°C, give about a third of the summer amount. At 22 to 26°C, give about half.
Can I Release My Harvester Ants?
No. A colony raised indoors won't survive outside, and this species doesn't belong in the wild here. 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 Pogonomyrmex bicolor good for beginners?
No. It is an advanced species for adult keepers only, because it has a very painful sting. For a first harvester colony in the UK, Messor barbarus is far easier and has no sting.
Can I buy Pogonomyrmex bicolor in the UK?
No. Pogonomyrmex bicolor is a North American ant and Best Ants UK does not sell it. It may be illegal or impossible to bring into the UK, so please never try to import it.
What do Pogonomyrmex bicolor eat?
Seeds are their main food, from a harvester seed mix bought from an established ant-keeping supplier. Add Protein Jelly once a week and organic honey or Ant Nectar once a week on another day. Always feed in the outworld only.
What temperature do Pogonomyrmex bicolor need?
Keep the nest at 26 to 30°C. Most UK homes are cooler than that, so use the Advanced Heating System Small set to 28°C under one quarter of a horizontal nest, opposite the watering area.
Do Pogonomyrmex bicolor hibernate?
They need a winter rest of 2 to 3 months at about 17 to 18°C, not a cold hibernation. Never let them drop below 15°C. A queen in her first year stays warm through her first winter.
Do Pogonomyrmex bicolor sting?
Yes, and it is very painful. In some people it can cause an allergic reaction. Keep this species for adults only, never handle the ants, and keep the outworld lid closed at all times.
Start Your Own Harvester Ant Colony
Print this guide and keep it next to your ant farm. In the UK, the easiest way to enjoy harvester ants is a colony of Messor barbarus, with no sting to worry about.
👉 Ready to start? Our A7 Plus ant farm kit has a pre-installed digital meter and a Nest + Outworld option, and it makes a superb home for harvester ants. 👉 Explore all our free ant care sheets.
