Ants are cold-blooded insects that need the sun’s heat to keep them warm. So, what happens to ants in winter when the temperature drops?
If you live in an area where temperatures stay below 75°F (24°C) in winter, ants often become inactive and hide in their nests. If you live in a warmer or tropical climate, ants can stay fully active and productive throughout winter at temperatures between 75 and 95°F (24 – 35°C).
Unlike many believe, ants do not die off in winter.
An ant can live for several years, with many queen ants living twice as long as their workers. This means that ants in cold climates need to survive many icy winters over their long lifetimes. Lucky for them, ants have found a few innovative and interesting ways to adapt to the cold and stay alive.
Surviving in winter starts in summer, so let’s start there too…
What ants eat in summer and fall
Adult ants cannot eat solid foods. They swallow liquids for food, such as nectar, honeydew, and juices from the solid food they feed to their young.
Ants digest some of this liquid food for themselves. The rest is stored in a second stomach, called a social stomach or a crop. They then share this stored liquid with other ants in the colony through mouth-to-mouth contact.
In warmer climates, ants treat all seasons the same, and nothing much changes with the foods they eat or what they do in summer and fall.
In colder climates, ants naturally start to eat more food in summer and fall, especially sugary, carbohydrate-rich foods. Their bodies store this food as fat, which is designed to give them the energy they need to stay alive when winter comes.
By the end of fall, the queen or queens have stopped laying eggs, so there are no young ants to take care of. Worker activity halts, and the entrances to the nest close because they are not being used.
All the ants in the colony prepare to snuggle down for winter.
Where ants go in winter
If the winter isn’t very cold, the ants live in a tropical climate, or the ants have built a nest in your home or car where the temperature is warm and controlled, the ants will carry on with their usual activities in winter.
Temperatures need to stay in the region of 75 and 95°F (24 – 35°C) for ants to carry on as a fully active colony.
If you see ants on a cold winter’s day outside, there was probably some warm weather that tricked them into thinking spring had arrived and it was time to leave the nest. But if you see ants inside on a cold day, you probably have an active ant nest in your home.
Let’s find out where outdoor ants go when there’s a cold winter…
As the temperature drops outside, so do the ants’ body temperature.
By the time winter temperatures reach 50°F (10°C), ants are lazy and very slow. Ants don’t sleep through winter or hibernate like other animals. Instead, they go into what’s called “diapause”, where their metabolism slows down, all work and development stops, and the ants stay as still as possible.
Ants don’t need much energy at this stage because they don’t move around much, so they can live off the fat they stored in summer and fall.
Ants have two ways to stay warm and survive a cold winter:
- Ants with underground nests go deep underground – at least 4 feet under. This is a safe zone during winter because temperatures are warmer and steadier in soil and rocks than they are above ground, where wind and air really make it icy cold.
- Some ants, especially those that live in shallow nests or above ground like carpenter ants, make glycerol in their blood in winter. Glycerol is made of sugar and alcohol, and it’s been likened to the antifreeze of ants because it stops ice from forming in their veins and damaging their bodies. (It’s interesting to note that some snails also use glycerol to get them through winter)
The following video was made by an ant farm keeper, who shows how ants survive extremely cold winters (he lives in Canada):
Ants leave their nest in spring
When spring arrives and the ground starts warming up, ants become more active and start getting back to work.
Worker ants open the exits to the outside world.
Over the course of the season, ants leave the nest to find food and set ant trails, take care of the nest and the young, and get swarmers or flying ants ready to leave the nest and start their own nests in late spring or early summer.
How to get rid of ants in the house in winter
If you have ants in your house in winter, it means the ants are part of an active colony and you can use traditional methods to get rid of them. Here are some pro tips and effective products that are available on Amazon to try:
Watch where the ants go, to find out where the ant colony is hiding. This may be inside a wall, in your cabinets, in a door or window frame, or even under floors. Ants come into your home for two important things: food and protection.
The ants you see in your home are foragers, and they are looking for food. Once you have found the ant trail that these ants follow, put ant bait stations along the trail so the foragers take the poison back to the nest and poison the colony.
Spraying ants with ant spray won’t be effective as you will only kill the ants you see. This won’t have any effect on the ant colony in the nest.
If you live in a warmer climate and you have ants outside in winter, sprinkle these granules around the outside of your home to kill ants for up to three months.
Once you know where the ants are living and you’ve killed them off, seal any cracks or holes in your home so more ants don’t move in.
If nothing you do seems to work, then you probably have a major ant infestation in your home or yard, and you will need to get in touch with a professional pest controller to get rid of the problem for you.