If you've noticed squirrels darting across your yard on a cold January morning, you already know the answer: most squirrels don't hibernate. The grey, red, and fox squirrels that visit backyard feeders stay active straight through winter. They just get better at hiding it. Ground squirrels and chipmunks are a different story — those species truly do shut down for the season. Here's how to tell them apart, and what's actually happening in the trees above your yard right now.
The short answer: tree squirrels don't hibernate
Grey squirrels, red squirrels, and fox squirrels — the ones you're used to seeing on a fence line or raiding a bird feeder — remain awake and active all winter long. They don't drop into a deep sleep, and their body temperature stays close to normal. What changes is their behavior: less time out in the open, more time in shelter, and a heavy reliance on food they buried weeks or months earlier.
Ground squirrels and chipmunks are the true hibernators. They dig underground burrows, lower their body temperature and heart rate dramatically, and spend long stretches of winter in a state of deep dormancy. It's a completely different survival strategy from the one tree squirrels use, even though the names sound similar.
Where do squirrels go in the winter?
Tree squirrels split their time between two kinds of winter shelter, and which one they choose depends on the weather and the individual squirrel.
Dens in tree cavities
Natural hollows in mature trees make excellent winter dens — insulated, dry, and protected from wind. A squirrel often maintains more than one den across its territory and rotates between them. A well-placed nest box earns its keep here too: a habitat with solid walls and a tight, weatherproof design gives squirrels the same protection a tree cavity would, in yards where old hollow trees are hard to come by. Our squirrel house guide covers what makes a nest box worth using through the coldest months.
Dreys in the branches
When a tree cavity isn't available, squirrels build a drey — a rounded nest of twigs, leaves, and bark lined with softer material like moss or shredded bark. Dreys are quicker to build than they look sturdy, but a well-constructed one holds up through wind and snow. You'll usually spot them wedged high in a fork of branches, close to the trunk for extra stability.
During a serious cold snap, tree squirrels hole up in a den or drey for a day or two, living off body fat and nearby food stores rather than venturing out. That's not hibernation — it's waiting out bad weather, and they're back foraging as soon as conditions ease.
Caching: the real winter strategy
Since tree squirrels stay active instead of sleeping through winter, they need a food supply that doesn't depend on the weather cooperating. That's where caching comes in.
Through fall, squirrels scatter-hoard: burying individual nuts and seeds across dozens or hundreds of separate spots rather than storing everything in one place. Scattering the food this way means a single raid by another animal, or one forgotten spot, doesn't wipe out the whole supply. Squirrels rely on scent and spatial memory to relocate their caches once the ground is covered in snow.
Consistent food access matters most around the first hard frost, before caches are fully built up, and again in late winter, when stores run low. Our guide to what to feed squirrels year-round breaks it down season by season.
Torpor vs. true hibernation
It helps to separate three different things that get lumped together as “hibernation”:
- True hibernation — seen in ground squirrels. Body temperature and heart rate drop sharply, and the animal stays in a den underground for long stretches without eating, living entirely off fat reserves.
- Intermittent torpor — seen in chipmunks. They den up for winter and enter lighter dormant periods, but they wake every few days to eat from food they stored in the den rather than fasting the whole season.
- Staying active with short shelter breaks — seen in tree squirrels. No drop in body temperature, no extended dormancy. Just normal activity, paused briefly during the worst weather.
Grey, red, and fox squirrels fall firmly into that third category. If a squirrel in your yard disappears for a few days during a cold spell and then turns up again looking for the feeder, that's exactly what should happen.
Why winter shelter matters
A tree squirrel that stays active all winter still needs somewhere dry, insulated, and out of the wind to retreat to overnight and during storms. In neighborhoods where mature trees with natural cavities are limited, that shelter gap is one of the biggest factors in how well squirrels get through the season. A nest box positioned on a trunk or sturdy pole, facing away from prevailing wind, gives squirrels a den option that a young or heavily-pruned tree can't provide on its own.
If you're deciding whether your yard needs a dedicated habitat, a feeding station, or both, our comparison of a squirrel house vs. squirrel feeder walks through what each one actually does for the squirrels using your yard.
What you can do this winter
A few adjustments make a real difference for the tree squirrels active in your yard right now:
- Keep feeders stocked through late winter, when cached food is running low and natural forage is scarce.
- Offer a nest box positioned 15–20 feet (4.5–6 meters) up a trunk, angled away from the wind, as a den alternative to tree cavities.
- Leave leaf litter and brush piles at the base of trees — squirrels use this material to build and repair dreys.
- Avoid disturbing a den or drey once you've spotted one; squirrels return to the same shelter repeatedly through the season.
For a broader look at drawing squirrels to your yard year-round, not just in winter, see our guide on how to attract squirrels to your backyard.
If you're setting up a habitat and a feeding station in one, the cedar Squirrel House Hideout Feeder combines a den-style shelter with a built-in feeding perch, giving squirrels both a place to shelter and a reliable food source in the same spot.
Tree squirrels aren't sleeping the winter away — they're out there, working off the food they buried months ago, and ducking into shelter only when the weather forces the issue. A degree of support from your yard, in the form of stocked feeders and a solid habitat, makes that whole system easier for them to run.
