Squirrels are energetic, bushy-tailed rodents found in various environments across the globe, excluding only Antarctica and Australia. As familiar sights in both urban parks and natural forests, their constant activity during daylight hours leads many to wonder about their rest periods. Most species are classified as diurnal, meaning their primary period of wakefulness and foraging occurs throughout the day. This active schedule requires restorative sleep, which is primarily taken when the sun sets and their natural predators are more active.
The Daily Sleep Schedule
Adult squirrels generally sleep for a total duration of 12 to 15 hours daily. This rest is not consolidated into one long stretch, but divided into several phases throughout a 24-hour cycle. The most sustained and deepest period of sleep takes place at night when they retreat to their sheltered nests. Daytime activity is interspersed with brief, vigilant naps that help conserve energy between bouts of foraging.
Juvenile squirrels require more sleep to support their rapid physical growth and development. Baby squirrels may rest for 14 to 16 hours daily, especially during their first few weeks of life.
Seasonal Adjustments and Hibernation
The sleep pattern of a squirrel changes with the onset of colder weather and resource scarcity. Winter survival strategies involve various forms of dormancy, which differ depending on the species. Tree squirrels, such as the common gray and fox squirrels, do not engage in true hibernation, but instead enter a lighter state known as torpor.
Torpor is a temporary physiological shift where the animal’s metabolism slows down and its body temperature decreases, though not as drastically as in true hibernation. This state is easily reversible, allowing the tree squirrel to wake up and forage during warmer days to access stored food caches. Their metabolic rate may drop to around 30% of their active rate, providing an energy-saving benefit.
Ground squirrels are true hibernators, entering a profound state of dormancy that can last for months. During hibernation, the heart rate and breathing slow dramatically, and the body temperature drops to just a few degrees above the surrounding environment. Their metabolic rate can decrease to as low as 2% to 6% of the active rate. Hibernation is not continuous sleep, as ground squirrels experience brief, periodic wakeful periods lasting 12 to 20 hours per week for physiological maintenance.
Sleeping Locations and Safety Behaviors
The location a squirrel chooses for rest is directly related to its species and its need for safety from predators. Tree squirrels build their nests, called dreys, high up in the forks of tree branches using twigs, leaves, and grass. They may also utilize natural tree cavities or hollows, which offer superior protection and warmth, especially during the winter months.
Ground squirrels construct elaborate underground burrows that feature complex tunnel systems and multiple chambers for sleeping, storage, and waste. These subterranean homes provide excellent defense against above-ground predators and insulate the animal from temperature extremes.
Both tree and ground squirrels build multiple sleeping locations to ensure a quick retreat is available should a primary nest be compromised. Because squirrels are prey animals, their sleep is characterized by vigilance and a quick readiness to awaken. When resting, a tree squirrel curls its body into a tight ball and wraps its bushy tail around itself to conserve body heat.