Squirrel dreys: the leaf nests that show up in bare trees

Why this time of year

From late October, as the canopy comes down, dreys that were invisible all summer stand out against the sky, and you can often find several along one street or in one patch of woods. Mass Audubon says squirrels would rather spend the coldest months in a tree cavity and will stick with a drey when no such shelter is available, gathering together in it to conserve heat, so a nest you find full in November may be abandoned for a hollow by midwinter.

How to notice it

1. Scan the bare crowns of oaks and maples, close in to the trunk or where two thick limbs fork. You want a rough ball of leaves about a foot or two across, twenty feet up or higher.
2. Look for the door, and expect not to find it. Mass Audubon and Northern Woodlands both describe the entrance as a small hole kept flush against the trunk or branch, so from the ground you are usually looking at the blank side of the nest.
3. Tell it from a bird nest by what it is built of. A drey is fully enclosed and made mostly of leaves; a crow's nest is an open platform of twigs and thin branches rather than foliage. Hawks build open nests too, and they often work leaves in, so shape and material together are the test rather than either alone.
4. Come back on a bright cold morning and watch one nest for a few minutes. An active drey has squirrels going in and out.

Sources

• massaudubon.orgMass Audubon. Size and placement verbatim: can be a foot or two wide and are usually located 20 feet or higher, built near the trunk or at the fork of two strong branches. The entrance: the squirrels enter the drey through a hole facing the trunk. And the winter-shelter preference: they prefer to spend the cold months in a more protected place, like a tree cavity, and if such permanent shelter is not available they will stick with a drey, often gathering together to conserve heat.
• massaudubon.orgMass Audubon squirrel overview. Drey size and height, and that dreys are sometimes used as temporary quarters in winter if a food supply is nearby. NOTE the condition this page states is a nearby food supply, NOT the absence of a cavity; the no-cavity condition comes from the news article above. This is the effective URL: the path /learn/nature-wildlife/mammals/squirrels that this entry was drafted against serves 200 only via a redirect and was already stale on 2026-09-13.
• audubon.orgNational Audubon. That once leaves drop in the fall, spotting nests in deciduous trees is easy; that a drey is built mostly of leaves while crows use twigs and thin branches, not foliage; and, cited against this card's own first draft, that Red-tailed Hawks favor sticks though they often incorporate leaves.
• northernwoodlands.orgNorthern Woodlands. That squirrel dreys are fully enclosed, that squirrels typically make the entrance small and flush with a tree trunk or branch, that squirrels rear their kits in them, and that by midwinter squirrels have mostly abandoned their dreys for the more effective shelter of tree hollows.
• content.ces.ncsu.eduNC State Extension. Construction method verbatim: making a stick frame that is then filled with dry leaves and lined with leaves, strips of bark, corn husks, or other materials. Also that gray squirrels prefer cavity dens over leaf nests when available.
• extension.psu.eduPenn State Extension. Independent confirmation of the same stick-frame-filled-and-lined construction, alongside use of tree cavities and nest boxes.

Checked against these sources on September 13, 2026.

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