Squirrel Nests: Everything You Need to Know
What are they made of, where do squirrels build them, how many squirrels live in one — and what should you do if you find one on your property?
⚡ Quick Answer
A squirrel nest — called a drey — is a round ball of woven leaves, twigs, bark, and moss built high in the fork of a tree. Squirrels build dreys for shelter, warmth, and raising young. They typically build multiple nests and may share them in winter for warmth. If you find one, leave it alone — it's almost certainly occupied or in use.
📋 What You'll Learn
Look up into the bare branches of a hardwood tree in winter and you'll almost certainly spot one — a dense, dark ball of leaves wedged into a high fork, looking like nature's own version of a treehouse. That's a squirrel nest, and it's one of the most fascinating structures in your backyard wildlife world.
On our 30-acre Michigan habitat we have dozens of squirrels, and watching them build, maintain, and share these nests across the seasons is endlessly interesting. Here's everything you need to know about squirrel nests — from what they're called to what you should do if you find one.
What Is a Squirrel Nest Called?
A squirrel nest is called a drey (pronounced "dray"). The word comes from old English and refers specifically to the leaf-and-twig nests that tree squirrels build above ground. You may also hear them called squirrel dens when they're built inside a tree cavity rather than on an open branch.
🌿 Drey
An outer nest built from leaves, twigs, and bark — the kind you see high in tree branches. Most common type.
🌳 Den
A nest built inside a hollow tree cavity. Warmer and more protected than a drey — preferred in winter.
🏠 Ground nest
Some squirrel species like thirteen-lined ground squirrels burrow underground instead of nesting in trees.
🐣 Nursery nest
A specially built or reinforced nest where a female raises her young — typically more insulated and secure than a regular drey.
What Does a Squirrel Nest Look Like?
From the ground, a squirrel drey looks like a large, roughly round ball of dead leaves — similar to a bird nest but much bigger and messier. Here's what to look for:
Size
Most dreys are about the size of a football — roughly 12 to 19 inches in diameter. Nursery nests used for raising young are often larger, sometimes up to 24 inches across.
Shape
Roughly spherical with a small entrance hole on one side. Unlike a bird nest which is open at the top, a drey is fully enclosed — more like a hollow ball than a cup. This keeps the interior warm and protects young squirrels from rain and predators.
Color & Appearance
Fresh dreys are green-brown from live leaves. As they age they turn gray-brown. In winter when trees are bare, dreys are easy to spot — look for that dark clump of compressed leaves high in the canopy, usually 20 to 45 feet off the ground.
Where Do Squirrels Build Their Nests?
Squirrels are strategic about nest placement. They need height for safety, structural support for stability, and proximity to food sources. On a private property or woodland habitat like ours, you'll typically find dreys:
- In the fork of major branches — the most common spot, usually where two large branches meet the trunk. The fork provides a natural cradle that keeps the nest from falling.
- 20 to 45 feet off the ground — high enough to avoid most ground predators, not so high that wind becomes a serious problem.
- In hardwood trees — oak, maple, beech, and hickory are favorites, partly because of their structure and partly because they produce the nuts squirrels eat.
- Near the trunk — placement close to the main trunk is more stable than out on the end of a branch.
- In tree cavities — a hole in a dead or living tree is premium real estate for a squirrel. Cavity dens are warmer, more hidden, and better protected than open dreys.
🏡 On Your Property
If you have mature hardwood trees — especially oaks — you almost certainly have squirrel nests. Look up into bare branches in late fall or winter when leaves are gone. That large dark clump that looks like it doesn't belong? That's a drey. On our Michigan habitat we can count dozens from the field in January.
What Are Squirrel Nests Made Of?
Squirrels are remarkable builders. A drey has two distinct layers — an outer shell and an inner lining — each made from different materials for different purposes.
🌿 Outer Shell
Woven twigs, leaves, and bark strips. This rough outer layer provides structural support and waterproofing. Squirrels weave branches together so tightly the nest holds its shape even in strong wind.
🪺 Inner Lining
Soft moss, grass, feathers, shredded bark, fur, and plant fibers. The inner layer is dense and insulating — temperatures inside a well-built drey can be significantly warmer than outside air.
Squirrels continuously maintain and add to their nests. After rain they may add dry material to the interior. Before a litter is born a female will dramatically reinforce and enlarge the nest. It's a living, evolving structure — not something built once and forgotten.
Squirrel Nesting by Season
Spring
First litter of the year born February–April. Female builds or reinforces a nursery nest. Young stay in nest 10–12 weeks.
Summer
Second litter born June–August. Squirrels may use lighter leaf nests. Young from spring litter become independent.
Fall
Heavy nest building and reinforcement before winter. Squirrels gather extra nesting material and begin caching food nearby.
Winter
Multiple squirrels may share a den for warmth. Cavity dens preferred over open dreys. Squirrels don't hibernate — they stay active on warmer days.
How Many Squirrels Live in a Nest?
It depends on the season and the type of nest:
- Summer dreys: Usually just one adult squirrel, or a mother with her current litter of 2–4 young.
- Winter dens: Multiple squirrels — sometimes 6 to 9 — will share a cavity den for warmth. This is unusual behavior for a normally solitary animal, driven entirely by survival instinct in cold climates.
- Nursery nests: A mother and her litter only. Males are not involved in raising young and are not welcome in the nursery nest.
Squirrels are generally territorial about their nests — each animal maintains its own dreys and knows exactly where each one is. The winter communal denning is the exception to this rule, not the standard.
What to Do If You Find a Squirrel Nest
The best thing you can do if you find a squirrel nest — in a tree, in your attic, or on the ground after a storm — is leave it alone. Here's what to do in each situation:
Nest in a tree on your property
Do nothing. This is exactly where it belongs. Avoid trimming that tree during squirrel nesting season (February–August) if possible. If you must trim, wait until fall when young are likely independent.
Nest in your attic or walls
This one needs attention but requires care. If there are young present, wait until they're old enough to leave on their own (around 10–12 weeks old) before sealing entry points. Contact a wildlife rehabilitator if you're unsure whether young are present.
Nest fallen from tree (storm damage)
Check for young squirrels inside. If babies are present and appear uninjured, place the nest in an open box and secure it as high up in the original tree as possible. The mother will return and relocate her young. If babies appear injured or the mother doesn't return within a few hours, contact a wildlife rehabilitator immediately.
Squirrel Nest vs Bird Nest — How to Tell the Difference
From the ground it can be hard to tell a squirrel drey from a large bird nest. Here's how to tell them apart:
🐿️ Squirrel Drey
Fully enclosed ball shape with a small side entrance. Large — football sized or bigger. Made of compacted leaves and twigs. Looks messy and dense from below.
🐦 Bird Nest
Open cup shape — you can see into it from below. Usually smaller and neater. Made of finer materials like grass, mud, and fine twigs. Visible in spring before leaves fill in.
Frequently Asked Questions
Do squirrels sleep in their nests every night?
Yes — squirrels return to a nest to sleep every night. They don't wander and sleep wherever they happen to be. Each squirrel knows exactly which of its several dreys it will use on a given night based on weather, safety, and proximity to food caches.
How long does it take a squirrel to build a nest?
A basic drey can be built in just a few hours. A well-insulated winter nest or nursery nest takes longer — sometimes several days of gathering and weaving material. Squirrels are remarkably fast and efficient builders.
Do squirrels reuse their nests?
Yes — squirrels maintain and return to the same dreys repeatedly, adding new material and repairing damage. However if a nest becomes heavily infested with parasites like fleas or mites, a squirrel will abandon it and build a new one nearby.
What eats squirrels in their nests?
Hawks and owls are the main predators that can reach squirrels in their dreys. Raccoons and snakes can also raid nests, particularly ground-level or low nests. This is why squirrels build high — and why having mature trees on your property is so important to healthy squirrel populations.
Can I put up a squirrel box to help them?
Absolutely — and it's one of the best things you can do for squirrels on your property, especially in areas where old hollow trees have been removed. A squirrel box mounted 20–30 feet up a mature tree gives squirrels a safe, warm alternative to an open drey. Check out our complete squirrel house guide for everything you need to know about putting one up.
Do squirrels nest in the ground?
Tree squirrels like gray squirrels and fox squirrels nest in trees, not the ground. However ground squirrels — a different species entirely — do burrow underground. If you're seeing burrowing activity in your yard, that's likely a ground squirrel, chipmunk, or vole rather than a tree squirrel.
What do baby squirrels look like in the nest?
Newborn squirrels are tiny, hairless, and pink — completely helpless at birth. They develop fur around 3–4 weeks and open their eyes at around 5 weeks. They stay in the nest for 10–12 weeks before venturing out. If you find one on the ground, check out our baby squirrel care guide for exactly what to do.
Types of squirrels, what they eat, do they hibernate, baby squirrels, black squirrels, squirrel houses and feeders — all in one complete guide from our 30-acre Michigan wildlife habitat.
Visit the Complete Squirrel Guide →