How to Care for Camponotus vicinus | The Variable Carpenter Ant Guide
Photo: Robert Webster / xpda.com, via Wikimedia Commons, licensed under CC BY-SA 4.0.
Often black-headed with a rusty red middle, Camponotus vicinus is one of the most widespread carpenter ants of western North America. Its colours change from place to place, from pale yellow-brown to almost black, which is how it got its common name.
Variable carpenter ants are calm, hardy and fun to watch. This guide explains Camponotus vicinus care step by step, from a founding queen in her test tube to a busy colony, including its winter rest.
We have kept ants since 1997, and the care rules here are the same ones we use for our own carpenter ant colonies every day.
👉 In a hurry? Download our free Camponotus vicinus care sheet (PDF) or open the Camponotus vicinus care sheet page for the key facts at a glance.
Camponotus vicinus at a Glance
Also known as: the variable carpenter ant
Origin: south-western Canada, the western United States and western Mexico
Keeping level: Beginner, with a good escape barrier
Queen: 14 to 16mm
Workers: 7 to 13mm, with big-headed majors at the top end
Colony: one queen, up to about 3,000 workers over many years
Nest temperature: 24 to 28°C
Nest humidity: 50 to 80%
Workers before moving into a nest: 3+ is a must, 5+ recommended
Winter: a rest from October to February at 5 to 8°C, only in a hibernation unit with precise control
Escape risk: strong climbers, so a PTFE barrier is a must
Meet the Variable Carpenter Ant
In the wild, Camponotus vicinus lives in meadows, open forest, desert scrub and riverside woodland, often high up in the hills. Unlike many carpenter ants, it mostly nests in the soil under stones, and only sometimes under fallen wood.
One colony can spread its chambers under several stones. The workers forage a lot at night, but they are often busy by day too. They look after aphids and scale insects and drink the sweet honeydew they make.
New queens fly out on their mating flights from late spring into summer. Now and then a few young queens start a nest together, but a grown colony keeps just one queen.
From egg to adult worker takes roughly two to three months, depending on warmth. A colony can live for around 15 years, so a healthy queen will be with you for a long time.
Can You Keep Camponotus vicinus in the UK?
Camponotus vicinus is a North American ant, and Best Ants UK does not sell it. North American ants may be illegal or impossible to import into the UK, and we never encourage importing ants.
This guide is for keepers who already look after this species where it is native, and for anyone curious about it. Every care rule here works just as well for the carpenter ants you can keep legally in the UK.
When a New Colony Arrives
The most important step: leave the parcel completely unopened, exactly as it arrived, at room temperature for 5 hours. The ants must adjust to the 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.
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. The ants are 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 exactly 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 queens can take a little longer.
Life in the Test Tube
Carpenter ant workers are big and capable from the start, so they don't need a huge colony before moving. Keep the ants in their test tube until there are at least 3 workers. That is a must. 5 or more workers is even better.
Don't worry if the queen's eggs have disappeared after delivery. Most carpenter ant queens eat their eggs in transit. This is normal for Camponotus, and only Camponotus. She lays again within 2 to 3 months of settling in.
A queen on her own 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 the queen and colony do far better afterwards. Keep her tube wrapped in its foil and disturb her as little as possible.
A queen in a test tube needs warmth too. If your room is cool, use a heating cable at the cotton stopper end of the tube only. Never lay a test tube on a heat mat.
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. Bit by bit, the tube becomes the bright spot and the dark nest becomes the safe home.
If the ants haven't moved 2 days after the tube is fully exposed, wrap the foil back on, wait another fortnight and repeat the whole process. Moving in happens on the ants' own time: anywhere 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. Ants sometimes leave a little brood behind.
The red filter and black cover stay on the nest all the time, so it is pitch dark inside. 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 Camponotus vicinus
Variable carpenter ants are strong climbers, so their home must be well made and escape-proof.
👉 Our Carpenter Ant Farm Starter Kit is made for carpenter ants, with a nest that has its own humidity and temperature meter, an outworld and a watering test tube.
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, and rooms with strong smells such as the kitchen.
Temperature and Heating
Keep the nest at 24 to 28°C during the active season. Warmth keeps the queen laying and the brood growing, and a cool colony grows very slowly.
Most UK homes are cooler than that for much of the year. 👉 The Advanced Heating System Small 4W holds the nest steady with its digital thermostat. Set it to 24°C.
The heat mat goes under one quarter of the nest only, on the side opposite the watering area. The ants can then pick the spot they like best. Never heat the whole nest.
In the outworld, aim for about 18°C overnight 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, because a big gap confuses the ants.
Water and Humidity
Keep the nest humidity at 50 to 80%. Use distilled or purified water only. Never use 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 little more in summer and a little less in winter. With a meter, simply water when the nest humidity drops below 50%.
Never water the outworld. Keep it dry, at about 50% humidity, like an average UK home. Carpenter ants should never have open water: give them a watering test tube in the outworld instead, never a water dispenser.
Feeding Your Variable carpenter ants
Carpenter ants have a real sweet tooth, and a growing colony needs plenty of protein too. 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. Honey and Ant Nectar are far better than sugar water or home-made mixes.
🥩 For the queen and brood, 👉 Cricket Mash is the more efficient protein for carpenter ants. 👉 Protein Jelly works well too. Keep protein jelly in the fridge at all times.
Serve food on a small piece of tin foil or in a 👉 small feeding dish, so leftovers are easy to lift out. Now and then, a rice-grain-sized piece of peeled grape or banana makes a nice treat.
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, dried mealworms (which are useless as ant food anyway), and live food from pet shops or online.
In our experience about half of all bought live food carries mites, so where you buy matters.
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.
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
Variable carpenter ants climb well, so escape prevention is a must. 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 small 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, because it foams. Roll it gently in your hands instead.
Winter Care
Camponotus vicinus comes from places with cold winters. Experienced keepers give it a rest from about October to February at a steady 5 to 8°C. That is only safe in a specialised hibernation unit with precise control, cooled down and warmed up gradually.
Without such a unit, keep the colony at room temperature in winter, with the heater on if your home is cool. Never put ants in a fridge, shed or garage, and avoid any abrupt temperature change. We never hibernate a queen in her first year.
Either way the colony slows down in winter, because its biological clock can't be tricked. During a full hibernation, give fresh water only and no food.
If the colony slows down, feed a little less, but never guess. At 17 to 22°C, give about a third of the summer amount. At 22 to 26°C, give about half, still twice a week.
Can I Release My Ants?
No. A colony raised indoors won't survive outside, and a North American ant 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 Camponotus vicinus good for beginners?
Yes, for a patient beginner. The ants are calm, hardy and easy to feed. They need steady warmth in the active season, a good escape barrier, and a proper winter rest only in a hibernation unit with precise control.
Can I buy Camponotus vicinus in the UK?
Best Ants UK does not sell this species. It is a North American ant, and it may be illegal or impossible to import into the UK. We never encourage importing ants. Choose a species that is legally kept and sold in the UK instead.
How many workers does Camponotus vicinus need before moving into a nest?
At least 3 workers is a must, and 5 or more is recommended. Carpenter ant workers are capable from the start, so they settle into an ant farm sooner than smaller species.
What temperature do Camponotus vicinus need?
Keep the nest at 24 to 28°C in the active season. Most UK homes are cooler than that, so an Advanced Heating System set to 24°C under one quarter of the nest is needed for most of the year.
Do Camponotus vicinus hibernate?
Yes. Experienced keepers give them a rest from about October to February at 5 to 8°C, but only in a specialised hibernation unit with precise control, and never in the queen's first year. Otherwise keep the colony at room temperature.
Why did my Camponotus vicinus queen eat her eggs?
Most carpenter ant queens eat their eggs during delivery. This is normal for Camponotus, and only Camponotus. Once she settles in, she lays again within 2 to 3 months.
Do variable carpenter ants sting?
No, they have no sting. The bigger workers can give a small nip with their jaws. They can also spray a little formic acid when disturbed. As with every ant, never handle them.
Ready to Start Your Own Carpenter Ant Colony?
Variable carpenter ants are not sold by Best Ants UK, but the same care brings our UK carpenter ant colonies to life.
👉 Start with the A7 Plus ant farm kit. Its pre-installed digital meter shows the nest temperature and humidity at a glance, and if you already have your ants, choose its Nest + Outworld option. 👉 Explore all our free ant care sheets.
