They start to appear in fall and are in full view all winter into the beginning of Spring.

Usually, they're at least 20 feet up and one to two feet wide. Sometimes, several are scattered in the same tree while only one is seen taking up several big branches in another tree. But they're everywhere.

Unless you're in a warmer climate where all the birds fly south for the winter, chances are you're seeing a drey. Dreys are up in the trees all year long; however, they're hidden by leaves in the warmer months when everything is alive and in bloom.
According to the Massachusetts Audubon Society, those dreys are the homes of furry outdoor creatures our dogs like to bark at and chase. Yup, squirrels don't just live inside trees; they build nests like birds but on a much larger scale.
Jolana Miller/Townsquare Media
Jolana Miller/Townsquare Media
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Those dreys are most likely empty in the colder months as they're the summer homes for squirrels. It's where they disappear to when they run up trees after collecting acorns or just doing their curious squirrel things down on the ground. However, in the winter, they will live in dreys if they cannot find a tree cavity to spend the colder months.
As a matter of fact, according to the Massachusetts Audubon Society, when you see a large collection of acorns all in one place around a tree, chances are there's a squirrel drey above you. Also, that drey may have started as a bird's nest, and then when a squirrel family moves in, it makes it bigger by adding twigs and leaves.

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