Squirrels are primarily active during daylight hours, dedicating their nights to sleep and energy conservation. Understanding where these small mammals choose to sleep reveals their adaptability to various environments and changing conditions.
The Cozy Squirrel Home: Dray and Cavity Nests
Squirrels construct two primary types of shelters for sleeping and raising their young: dreys and cavity nests. A drey, also known as a leaf nest, is a spherical structure typically built in tree branches. Squirrels weave twigs together to form a platform, then pack damp leaves and moss onto it for stability. The exterior measures about 30 centimeters (12 inches) or more in diameter, with an inner cavity lined with softer materials like shredded bark, grass, leaves, or pine needles. These nests usually have one or two entrance holes, often oriented towards the tree trunk, with a second hole sometimes serving as an escape route. Dreys offer shelter and protection.
Cavity nests, or tree dens, are natural hollows found within trees. These can originate from naturally occurring tree decay or from abandoned spaces created by woodpeckers or other wildlife. Squirrels utilize these existing shelters, sometimes modifying them to suit their needs. Cavity nests generally provide superior protection from precipitation, wind, and cold temperatures compared to dreys.
Preferred Sleeping Spots: Trees, Attics, and More
Trees serve as the most common sleeping locations for squirrels, offering elevated positions away from ground predators. Dreys are frequently situated in the forks of tall trees, at least 20 feet above the ground. These leaf nests are often built close to the main trunk or where strong branches meet for added stability. Tree cavities, found in trunks or large branches, also provide secure and insulated sleeping quarters.
Beyond natural tree habitats, squirrels frequently seek shelter in human-made structures. Attics, chimneys, and sheds are common sleeping spots. Squirrels are drawn to these locations because they offer warmth, insulation, and protection from harsh weather and predators, especially when natural tree hollows are scarce in urban or suburban areas. Attics, in particular, provide a safe, secluded environment for raising young. Squirrels can access these areas through various entry points, including roof gaps, chimney openings, soffit damage, and attic vents.
Adapting to the Seasons: Winter and Summer Sleeping Habits
Squirrels adjust their sleeping habits and shelter choices in response to seasonal changes. During winter, they seek more insulated and secure locations to cope with colder temperatures. Deeper tree cavities are often preferred due to their superior insulation and protection from the elements. If cavities are unavailable, squirrels may fortify their dreys with additional materials to create a more robust winter nest. While squirrels do not truly hibernate like some other animals, they can enter a state of torpor during severe cold to conserve energy, waking periodically to forage for stored food, and may huddle together and share nests for additional warmth.
In contrast, summer sleeping habits are less focused on insulation. Squirrels may use lighter, more open dreys that offer adequate shelter without excessive warmth. Sometimes, they might even utilize simple platforms of branches or abandoned bird nests for resting. During the warmer months, squirrels may take multiple short naps throughout the day in addition to their main nocturnal sleep. In extremely hot and arid climates, some ground squirrel species may enter a state of estivation, a form of hot-weather dormancy, to conserve energy when food and water are scarce, highlighting their capacity to adapt their resting behaviors to a wide range of environmental conditions.