Have you ever noticed large, messy-looking bundles high up in trees during fall and winter? These clumps, often mistaken for bird nests, are actually squirrel dreys—cozy homes built by squirrels. While they’re present all year round, they become more visible when trees shed their leaves.
Let’s take a closer look at what dreys are, how squirrels use them, and why you’re more likely to spot them in colder months.
What Is a Drey?
A drey is a nest built by squirrels, typically made of twigs, leaves, moss, and bark. These structures are usually:
- At least 20 feet high in trees
- One to two feet wide
- Scattered throughout a tree, sometimes in multiple bundles
Dreys can often be seen during fall, winter, and early spring, when trees lose their leaves and expose what was hidden in the warmer months.
Why Do Squirrels Build Dreys?
1. Shelter During Warmer Months
According to the Massachusetts Audubon Society, squirrels primarily use dreys in the warmer months for protection and rest. These nests provide a safe space from predators like hawks and keep squirrels dry during rain.
2. A Backup Winter Home
Squirrels prefer tree cavities (hollowed-out parts of trees) to stay warm in winter. However, if they can’t find a tree hole, they reinforce their dreys and use them for warmth and survival.
3. Storage for Food
If you see a large pile of acorns near a tree, there’s a good chance a drey is above you. Squirrels often store food near their nests for easy access during colder months.
How Are Dreys Made?
Squirrels are excellent builders. Their dreys are strong enough to last through wind, rain, and snow. After winter, squirrels simply repair and reinforce their nests instead of starting from scratch.
Interestingly, some dreys start as bird nests. Squirrels then add more twigs and leaves to make them larger and sturdier for their families.
Where Do Squirrels Go in Summer?
In summer, you might see squirrels running up trees and disappearing into the leaves. That’s because their dreys are hidden by thick foliage, making them nearly impossible to spot.
Come fall, when trees shed their leaves, dreys suddenly become visible, surprising many people who didn’t notice them before.