Ever spot those leafy balls way up in tree branches and wonder what they’re called? Squirrel nests go by the name “dreys,” though some squirrels also use tree hollows, which folks call dens. Knowing these terms helps you tell a quick drey from a den and makes it easier to figure out where squirrels sleep, raise their babies, and stay safe.
Stick with me here and you’ll see how squirrels actually build their homes, what they use, and why they sometimes pick a drey instead of a den. Suddenly, every tree in your neighborhood might seem a little more interesting.
What Are Squirrel Nests Called?
Squirrel nests have two main names, depending on where you find them and how the squirrels build them. One name describes the leafy ball up in the branches, and the other is for a hollow or cavity inside a tree.
Definition and Origins of the Word Drey
People call the round, leafy nest in tree forks a drey. The word “drey” actually comes from old Germanic roots about resting or dwelling. In English, it’s meant a squirrel’s nest for a really long time.
Squirrels use twigs, dry leaves, grass, and sometimes moss to build dreys. They weave a messy outer shell from twigs, then stuff leaves and softer bits inside for insulation.
Dreys usually measure about 6–8 inches across inside, just big enough for a squirrel family.
You’ll find dreys high in tree branches, tucked in forks or where the branches meet the trunk. They’re easy to spot in parks and backyards. Some folks confuse them with bird nests, but dreys look bulkier and messier.
Difference Between Dreys and Dens
Dreys and dens both give squirrels shelter and a place to raise their young. The big difference? Location and protection.
A drey sits out in the open among the branches. A den, on the other hand, is a cavity inside a tree trunk or even in a building.
Dens give better protection from wind, rain, and predators because wood surrounds them. Squirrels prefer dens when they find hollow trees or old woodpecker holes.
Dreys are more exposed but quicker to build—handy when tree cavities aren’t around.
Mothers usually pick dens for winter and raising babies. Squirrels often use more than one nest in their territory—some dens, several dreys—for naps, backup shelter, or just to avoid parasites.
Types of Squirrel Nests
Squirrels build different types of nests, depending on their species and where they live. The main kinds are tree nests (dreys and dens) and ground nests (burrows) for ground squirrels.
Tree squirrels and flying squirrels usually build dreys or settle into dens.
Dreys: These are leafy, round nests built in branch forks. Squirrels use twigs for structure and line them with leaves, grass, or fur. Some people call them “leaf nests.”
Dens: These are hollows inside trunks or branches. They’re quieter, warmer, and safer. Squirrels line dens too.
Burrows: Ground squirrels dig underground tunnels, complete with chambers for nesting and storing food.
Sometimes, squirrels move into attics, wall spaces, or nest boxes when trees aren’t available. Many squirrels keep a few nests across their range, switching between summer and winter homes or dodging threats fast.
How Squirrels Build Their Nests
Squirrels grab whatever’s nearby—branches, leaves, plant material—to make warm, dry homes. You’ll spot their nests high up in forks or tucked inside hollows, always built with weather and predators in mind.
Nest Construction Process
Squirrels start by picking a site, usually 9–13 meters up in a tall tree. They work alone, gathering small branches and twigs and snapping them off with their teeth.
You’ll notice the frame comes first—a woven shell that holds its shape and keeps wind out.
Next, they bulk it up and add insulation. Squirrels tuck dry leaves and grass into the twig frame and pack the inside with softer stuff.
Building takes several days, and they repair the drey through the season. Sometimes, they even build a backup nest nearby, just in case.
Materials: Twigs, Leaves, and More
Twigs and leaves make up the outer wall. Squirrels prefer fresh, leafy twigs at first so the leaves stay on through winter.
You might spot shredded bark, pine needles, moss, or even fungal threads in certain spots.
For warmth, squirrels use grass, moss, feathers, shredded bark, and other soft fibers. In tree hollows and dens, you’ll see less twig work since the hollow acts as a shell.
Urban squirrels sometimes grab insulation strips or shredded paper from houses for their nests.
Inside a Drey: Nest Structure and Comfort
A finished drey looks like a hollow ball, about 30 cm across or so. The entrance hole usually sits near the bottom and faces the trunk to keep out rain.
Sometimes, there’s a second hole for a fast escape from predators.
Inside, the nest forms a shallow cup lined with soft materials. This cozy cup keeps babies and adults snug and helps hold in heat.
If squirrels use a tree hollow or den instead, they still pile in bedding for comfort and insulation. Used dreys need regular upkeep and can get fleas or lice, so squirrels sometimes move between nests.
Why Squirrels Build Nests
You build shelter to stay dry and warm, right? Well, squirrels do the same thing.
They put together nests to raise their young, grab some rest during the day, and escape storms or cold snaps. Dreys and tree cavities help them hide from hawks, raccoons, and whatever else the weather throws at them.
Squirrels actually change their nesting habits depending on the season and how safe they feel. In winter, you’ll spot them using tree cavities more often since those spots keep out the cold and protect newborns better.
They don’t just stick to one nest, either. Squirrels build several throughout the season—kind of like keeping a backup plan in case a drey gets damaged or overrun by pests.
Curious about how they put these dreys together or what materials they use? Check out this description of dreys in trees.
