Ever wondered where squirrels actually sleep during winter? Most tree squirrels stay active and curl up in insulated nests called dreys or in tree cavities, but some ground species hibernate deep underground. These choices help squirrels stay warm, safe, and give them access to their food stashes when the weather lets up.
Let’s take a look at where these nests hide, why squirrels pick certain spots, and how their sleep and survival habits shift once it gets cold. Maybe you’ll even spot a nest or two in your own yard. Squirrels have some pretty clever tricks for making it through winter, honestly.
Primary Winter Sleeping Spots for Squirrels
Squirrels choose places that keep them dry, warm, and away from predators. You’ll spot them using hollow trees, thick leaf nests, or even underground dens, depending on what’s around and how risky things feel.
Tree Cavities and Dens
Tree cavities offer strong protection from wind, rain, and cold. You’ll often find tree squirrels and flying squirrels tucked into hollows in older trees.
These cavities might start as old woodpecker holes or spots where the tree has decayed naturally. Squirrels line the inside with shredded bark, leaves, and a bit of fur for extra insulation.
Cavities cut drafts better than open nests, which can make a real difference. If you’ve got older trees with hollows nearby, you’re basically running a squirrel hotel in winter.
Sometimes a single squirrel moves in, but small family groups will share if the space allows. Birds and bats also want these spots, so the number of squirrels using them changes from year to year.
Leaf Nests and Dreys
Dreys are those classic, messy-looking leaf nests you see wedged into the forks of branches. Tree squirrels build them from twigs, leaves, moss, and sometimes even bits of insulation or string they find.
A good drey forms a rounded, layered shell that keeps rain out and holds warmth in. Squirrels usually build dreys in dense branches or close to the trunk to dodge the wind.
You’ll see dreys higher up in the canopy during summer, but squirrels move them deeper into sheltered branches for winter. Flying squirrels sometimes use dreys, though they usually go for cavities at night.
Some squirrel species will share dreys, especially when it’s freezing. Communal nesting pops up a lot among smaller squirrels on the coldest nights.
If you spot several dreys in one tree, you’ve probably got a healthy squirrel community in the area.
Underground Burrows
Ground squirrels and even some tree squirrels use underground burrows when things get rough up top. You’ll notice burrows as small mounds or holes near trees, banks, or just out in open ground.
Burrows keep temperatures steady and hide squirrels from predators. Inside, squirrels pack chambers with grass, leaves, or fur to insulate their sleeping spots.
Some burrows are simple, while others turn into complex tunnels with separate rooms. Ground squirrels are the champs here—they’re the ones most likely to hibernate or enter a long torpor in these dens.
If you manage a yard, check for burrow entrances before you landscape or mow. Blocking active burrows can trap animals, so wait until you’re sure they’re empty or get advice from wildlife pros.
Winter Nesting Behaviors and Survival Tactics
Squirrels have a few solid tricks to stay warm and fed when it gets cold. They might sleep alone or pile in together, build super-insulated nests, slow things down with torpor, or even sneak into buildings or nest boxes in cities.
Communal Nesting and Group Warmth
On really cold nights, you might notice several squirrels sharing a cavity or drey. Southern flying squirrels especially love to nest together and use soft little calls to keep track of each other.
Group nesting helps them share body heat, which is a lifesaver for small or young squirrels during a sudden cold snap. If you find a nest with multiple residents, it’s often adult females and juveniles huddling up in late fall and winter.
Sharing nests means each squirrel burns less fat and stays warmer. This matters most where winters drag on or food gets tight.
Nest Construction and Insulation
Squirrels build two main shelters: leaf-and-twig dreys wedged in branch forks and solid cavity nests inside tree holes or sometimes buildings. Dreys use layers of leaves, moss, and bark pressed tight to block wind and trap air for insulation.
Tree cavities get lined with softer stuff—fur, shredded bark, and dry leaves—for extra warmth. You can spot a drey by its round, compact shape high in the branches, usually with just one entrance.
When it pours, squirrels switch to cavities or nest boxes since wet leaves aren’t much help. If you’ve got squirrels in your attic, look for chewed entry points and seal them up to keep the critters outside.
Torpor and Winter Activity Patterns
Not all squirrels hibernate. Many use torpor, where they drop their body temperature and metabolism for a while. Ground squirrels and Arctic ground squirrels can hibernate for months.
Tree squirrels, like eastern grays, go into torpor for just hours or a couple days, then wake up to forage when the weather’s decent. You’ll notice squirrels get more active around midday on sunny days, coming out to check their food stashes.
Scatter-hoarding—burying lots of small caches—lets them survive on stored nuts through winter. Watch for more midday movement and less action at dawn or dusk during the coldest spells.
Adapting to Urban Environments
Urban squirrels often take over roofs, attic spaces, or nest boxes when they can’t find natural cavities nearby. You’ll see them raiding bird feeders or grabbing leftover nuts, so your yard might end up as their go-to winter snack spot.
If you’re hoping to help them out, set up a squirrel feeder somewhere away from your house’s eaves. Toss in some whole nuts—this usually keeps them out of your attic.
Want to keep squirrels from nesting in your place? Go around and seal any gaps bigger than a quarter inch. Toss a chimney cap on, too.
If you spot baby squirrels, call a wildlife rehabilitator before trying to move them. City squirrels tend to switch up their nesting spots a lot, bouncing between dreys, tree cavities, and even man-made hideouts, depending on the weather, predators, or whatever food they can find.
