Where Do Mice Go in the Winter? An Edmonton Homeowner’s Guide

Key Takeaways

• Mice don’t hibernate — they stay active all winter; they just relocate somewhere warmer.
• Outdoors, they burrow under wood piles, sheds, and brush. Once the cold really hits, most head straight for houses, garages, and sheds instead.
• Indoors, they nest in walls, attics, crawl spaces, and insulation — usually somewhere quiet that you rarely check.
• Edmonton’s cold snaps and older housing stock make this an easy season for mice to get comfortable.
• Sealing entry points before winter is still the best defence you’ve got.

So, where do mice go in the winter? Honestly, a lot of the time, the answer is: your house. Mice don’t curl up somewhere and sleep the cold away. The moment temperatures drop, they start hunting for the nearest warm, quiet spot with food close by, and once they find it, they don’t leave. If you’ve been hearing scratching in the walls since the first hard freeze, this is exactly why.

I’ve walked into a lot of Edmonton homes in January where the owner swears they’ve never had a mice problem before, and the truth is, the mice probably moved in back in October. It just took until January for anyone to notice.

Here’s what’s actually going on, where mice go once winter sets in, why your home is such an easy target, and what you can do about it before it turns into a full-blown infestation.

You can find a free mice control guide here: Free Guide To Mouse Control

Do Mice Hibernate Actually?

Nope. This is the one myth I hear constantly, and I get why — it seems logical. Bears hibernate, some rodents hibernate, so surely mice do too?

They don’t. Hibernation is a specific survival trick: an animal’s body temperature and heart rate drop way down, and it basically sleeps through the worst of the cold with no food needed.

Mice never picked up that skill. Instead, they stay wide awake all winter, which means they need a steady supply of food and a warm place to shelter for months on end. And that’s precisely why they show up indoors right when the weather turns.

So Where Do Mice Go in the Winter? The Reality

If They Stay Outside

Some mice do tough it out outdoors, but “tough it out” is doing a lot of work in that sentence. They’re not just wandering around in the snow. They dig in and find whatever cover they can:

• Wood piles and brush piles
• Compost heaps
• Underneath sheds, decks, and porches
• Tall grass, garden beds, and dense shrubs
• Old burrows dug by other rodents

These spots hold a bit of warmth and hide the mice from owls, hawks, cats, and the odd fox wandering through. But let’s be honest — Edmonton winters aren’t gentle. Once we’re looking at a stretch of -25°C or colder, outdoor shelter alone often isn’t enough, and that’s exactly when mice start eyeing your house.

If They Come Inside

This is where it gets real for homeowners. Once a mice finds a way in, it usually stops looking for anywhere better, because why would it? Your house has everything on its wish list — warmth, food, and soft material to build a nest. The spots I check first on every winter inspection:

• Wall voids and behind baseboards
• Attics and roof spaces
• Crawl spaces and basements
• Inside the insulation itself
• Behind the fridge, stove, or water heater
• Garages, sheds, and storage boxes

Mice aren’t picky builders. Give them shredded paper, fabric, chewed cardboard, or torn-up insulation, and they’ll turn it into a nest somewhere dark and undisturbed — usually somewhere you’re not opening up every day.

Why Edmonton Homes Are Such an Easy Target of Mice in Winter

A few things stack up against homeowners here specifically:

Our cold snaps are no joke. When temperatures fall well below -20°C, most outdoor shelter just isn’t cutting it anymore, even for a well-fed mice.

Food outdoors basically disappears. Once the ground freezes, the seeds, insects, and plants mice rely on all summer are gone. Your pantry, by comparison, looks like a five-star buffet.

A lot of our housing stock is older. Foundations settle, weatherstripping wears thin, and gaps open up around utility lines — small stuff that’s easy to miss until a mice finds it first.

Attached garages are basically a welcome mat. Mice get into the garage, then work their way into the house through a shared wall or a gap under the door. It’s a two-step move, and I see it constantly.

Signs You Might Already Have Company

If you’re wondering whether mice have already moved in, here’s what to check for, especially in the quiet corners of the house nobody uses much:

• Small, dark droppings near food, in drawers, or along baseboards
• Scratching or scurrying sounds in the walls or ceiling at night
• Gnaw marks on food packaging, wires, or wood
• Shredded paper, fabric, or insulation balled up in a corner
• A stale, musky smell in enclosed spaces like closets or under sinks
• Greasy smudge marks along walls where mice travel the same path over and over

If more than one of these sounds familiar, there’s a good chance a nest is already somewhere in the house — you just haven’t found it yet.

How They’re Actually Getting In

This part surprises people every time: a mice only needs a gap about the width of a pencil to squeeze through. Here’s where they usually find their way in:

Entry Point	Why It’s a Problem
Gaps around pipes or vents	Common in older Edmonton homes, and rarely sealed the first time properly
Cracks in the foundation	Freeze-thaw cycles widen these year after year
Garage door seals	Rubber weatherstripping shrinks and cracks in cold weather
Gaps around wires entering the home	Often missed during construction or renovation work
Torn or loose window screens	Quiet, easy to overlook, and right at their level

A Winter Prevention Checklist You Can Actually Do Yourself

Most of this is safe to handle on your own, and honestly, it’s worth doing before the deep freeze sets in, not after:

• Seal gaps around pipes, vents, and wires with steel wool or caulking
• Check your garage door seal and replace it if it’s cracked or gapping
• Keep firewood and brush piles away from the house, not stacked against it
• Store pantry food in airtight containers instead of bags or boxes
• Clean up pet food and bird seed spills right away
• Trim back branches and shrubs that are touching the house

If you’ve already got activity in the walls, though, DIY prevention usually isn’t going to cut it on its own. That’s the point where a real inspection makes the difference between dealing with one mice and dealing with a nest of them come spring.

How We Handle a Mice Infestation

At Major Pest Control, our winter mice process is pretty straightforward: we inspect the property to find where they’re getting in and where they’ve nested, treat and remove the current problem, seal up the entry points so it doesn’t happen again, and follow up to make sure it actually stuck.

If you’re hearing something in the walls in Edmonton, Calgary, or Red Deer this winter, our mouse control service can take it from inspection to done.

The Bottom Line

Mice don’t vanish for the winter — they just move somewhere warmer, and a lot of the time, that’s your house. Once you know where they go and why, it’s a lot easier to catch the signs early and seal things up before one mice turns into a whole nest behind your drywall.

If you’re already hearing them, don’t wait it out hoping they’ll leave on their own. They won’t. The sooner it’s handled, the less cleanup and damage you’re dealing with come spring.

Frequently Asked Questions

Do mice hibernate in winter?
No, mice don’t hibernate. They stay active year-round, relying on shelter and a steady food supply rather than shutting down for the season. That’s exactly why mouse activity tends to pick up indoors once the weather turns cold.

Where do mice hide in a house during winter?
Mice typically nest in wall voids, attics, crawl spaces, insulation, and behind larger appliances like the fridge or stove. They go for dark, quiet spots close to food, which is why basements, garages, and storage areas are common hiding places.

Do mice come back to the same nest every winter?
They can, especially if the spot stayed safe, warm, and undiscovered, and if the entry point they used was never sealed up. That’s part of why sealing gaps after removal matters just as much as the removal itself.

Can mice survive an Edmonton winter outdoors?
Some do, burrowing under wood piles, sheds, or thick brush. But our cold snaps make it a rough gamble, and plenty of mice that start the season outside end up moving into a home, garage, or shed once temperatures really drop.

How do I know if mice are in my walls?
Listen for scratching or scurrying at night, and watch for a musky smell in enclosed spaces or droppings along baseboards. If the noise keeps coming from the same spot in a wall or ceiling, it’s worth getting an inspection before it spreads.