Most ants disappear the moment the weather turns cold. Prenolepis imparis does the opposite. Known as the winter ant, this small, shiny ant is often the first one you see out foraging in early spring, sometimes with snow still on the ground, and the first to vanish underground when summer gets hot. It also has a clever trick: some of its workers turn into living food storage tanks, which is why it is also called the false honey ant.
In this guide you will learn how to identify winter ants, where they live, how they behave, how they breed, and how to keep a healthy colony in an ant farm.
Quick facts
- Scientific name
- Prenolepis imparis
- Common names
- Winter ant, false honey ant, small honey ant
- Native range
- Much of the United States, southern Canada and northern Mexico
- Worker size
- About 3 to 4 mm
- Queen size
- Much larger than workers, with a big, round abdomen
- Colour
- Shiny light to dark brown
- Queens per colony
- Often one, but wild colonies can have several
- Colony founding
- Claustral, the queen raises her first workers alone
- Ideal temperature
- 18 to 24 °C, they dislike heat
- Winter rest
- Recommended, about 2 to 3 months at 5 to 10 °C
- Diet
- Sugars, honeydew, fruit and insects
- Growth speed
- Slow to moderate
- Difficulty
- Beginner to intermediate
How to identify a winter ant
Winter ants are small, glossy and fast moving, with long legs and long antennae. Their colour ranges from honey brown to dark chocolate brown, and their bodies have a smooth, polished shine.
The best clue is the shape of the thorax. Seen from the side, it is pinched in the middle, giving it an hourglass look. Very few common ants have this shape, so once you notice it you will start spotting winter ants everywhere.
- Workers: about 3 to 4 mm, all roughly the same size
- Repletes: workers with a hugely swollen, almost see through abdomen full of stored food
- Queens: much bigger than workers, with a large, rounded abdomen packed with fat reserves
- Males: small, dark and winged, only produced by mature colonies
Where they live
Winter ants are found across much of the United States and reach into southern Canada and northern Mexico. They like shady, sheltered places with good soil, such as forests, forest edges, parks, older neighbourhoods with mature trees, and lawns near shrubs.
Their nests are underground and can be remarkably deep. Researchers digging up winter ant nests have found chambers more than 3 metres below the surface. The entrance is usually a small hole surrounded by a little crater of soil, often hidden under leaf litter or at the base of a tree.
That deep nest is the secret to their unusual schedule. Deep soil stays cool in summer and never freezes in winter, so the colony can always retreat to a comfortable temperature.
Behaviour and colony life
Winter ants are famous for being active in the cold. They have been recorded foraging at temperatures only a few degrees above freezing, at times of year when almost no other ant is out. They take advantage of this quiet season to collect food without competition.
When summer heat arrives, the colony does the opposite of most ants. Foraging slows down or stops, and the workers seal or ignore their entrances and stay deep underground until it cools off again in the fall. This summer rest is sometimes called aestivation.
Other behaviours worth knowing:
- Peaceful with people: winter ants are timid and do not sting. They can bite, but their jaws are too small to bother a person.
- Tough against invaders: researchers in California found that winter ants can hold their ground against the invasive Argentine ant by using a defensive chemical secretion. That makes them one of the few native ants able to resist it.
- Team foraging: workers lay scent trails to good food sources and recruit nestmates, so you will often see neat lines of ants heading to the same spot.
The false honey ant: living food storage
One of the most fascinating things about this species is its repletes. Some workers drink far more food than they need and store it in their stretchy abdomen, which swells up like a tiny amber bead. During lean times, for example in the hot summer when nobody forages, these workers share their stored food with nestmates mouth to mouth.
This is why Prenolepis imparis is called the false honey ant. True honeypot ants hang from the ceiling of their nest and barely move. Winter ant repletes stay mobile and can still walk around the nest. Researchers have found they store a lot of fat, not only sugar, which helps the colony get through the summer and fuels the big spring mating season.
Seeing a few round, swollen workers in your farm is a great sign. It means the colony is well fed and saving food for later.
Breeding and life cycle
An unusual mating season
Winter ants have a mating schedule that is almost backwards compared to most ants. Winged queens and males are raised in summer and fall, then spend the whole winter inside the nest. Their mating flights happen in early spring, often on the first warm, sunny days, when few other insects are flying.
Founding a new colony
After mating, the queen breaks off her wings and digs a small chamber in the soil. She seals herself in and raises her first workers alone, without eating, using the large fat reserves she built up before her flight. This is called claustral founding.
From egg to worker
- Eggs: tiny and white, laid in small clusters
- Larvae: small, white and fed by the queen or workers
- Pupae: pale at first, slowly darkening before the adult emerges
- First workers: called nanitics, they are slightly smaller than normal workers
Development is slower than in many other species, especially at cooler temperatures. Young colonies grow at a steady pace and can reach a few hundred workers within a couple of years. Wild colonies can grow much larger and may have more than one queen.
Temperature, humidity and the summer slowdown
Because winter ants love the cold and dislike heat, they do best at normal room temperature or slightly cooler.
- Active season: about 18 to 24 °C. Avoid heating mats and warm windowsills.
- Too warm: above roughly 26 °C the colony may slow down and hide, just like it would underground in summer.
- Humidity: keep part of the nest nicely moist. These ants come from deep, damp soil and like higher humidity than many species.
- Outworld: can stay dry, with a small water source available.
Do not panic if your winter ants go quiet in July or August. A summer slowdown is completely normal for this species. Keep the nest moist, keep it cool and offer small amounts of food.
Winter rest
In nature, winter ants stay active on mild winter days, but they still go through a cold season. In captivity, a cool rest of about 2 to 3 months at 5 to 10 °C helps keep the colony on its natural rhythm and supports strong egg laying in spring. Lower the temperature slowly over a week or two, make sure the nest stays moist, and warm them back up slowly in spring.
Feeding
Winter ants have a sweet tooth, but they also need protein to raise healthy brood.
Sugars
- Honey water or sugar water
- Small pieces of ripe fruit such as apple, pear or grape, removed before they go mouldy
Protein
- Fruit flies, small crickets or pieces of mealworm
- Pre killed feeder insects from a clean source
Offer protein about twice a week and remove leftovers after about 12 hours. Because workers are small, chop insects into small pieces or crack them open so the ants can get to the soft insides easily.
Keeping them in an ant farm
Winter ants are a great choice for keepers who want something a little different. They are peaceful, interesting to watch, and their cold loving lifestyle suits Canadian homes very well.
Your colony will arrive in a test tube. Most colonies can stay in it for 5 to 6 weeks. Keep it somewhere dark, quiet and away from heat. Once the workers fill the tube or the water runs low, move them into a small nest that holds moisture well.
Good homes for this species:
- Modular Ant Farm New Gen Small kit for a young colony
- Modular Ant Farm Forest Large kit as the colony grows
- Expansion modules to add space when needed
Workers are small, so make sure the farm is closed properly and all connections are tight. A small gap that a carpenter ant could never fit through can be an open door for a winter ant.
Watch them in action
In this video you can see winter ants up close, including their glossy bodies and the swollen repletes that give them the name false honeypot ants.
Keep your own winter ant colony
Our Prenolepis imparis colonies come with a queen and workers, raised by experienced keepers in Calgary and covered by our Live Arrival Guarantee.
Frequently asked questions
Why are they called winter ants?
Because they forage in cold weather, often in early spring and late fall when other ants are inactive. They have been seen foraging only a few degrees above freezing.
Why are they called false honey ants?
Some workers store food in their swollen abdomen and share it with the colony later. Unlike true honeypot ants, these workers can still move around the nest.
Do winter ants bite or sting?
They do not sting. They can bite, but they are too small to hurt a person.
Why did my winter ant colony stop moving in summer?
A summer slowdown is normal for this species. In the wild they stay deep underground when it is hot. Keep the nest cool and moist and they will become active again as temperatures drop.
Do winter ants need hibernation?
A cool winter rest of about 2 to 3 months at 5 to 10 °C is recommended to keep the colony healthy and laying well in spring.
Are winter ants good for beginners?
Yes, as long as you keep them cool and the nest moist. They are peaceful, interesting and well suited to Canadian homes.
