Squirrels are known for their agile movements and resourceful nature, which extends to their impressive nest-building abilities. These carefully constructed homes play a significant role in a squirrel’s survival, providing refuge from predators and the elements. Their ingenuity in creating these arboreal dwellings highlights their adaptability and instinctual engineering skills.
Different Kinds of Squirrel Nests
Squirrels primarily construct two main types of nests: dreys and den nests. Dreys appear as large, spherical masses of leaves and twigs high in tree branches. They are typically found nestled in the forks of large branches or close to the main trunk, providing stability and camouflage.
Den nests, in contrast, are established within existing tree cavities, such as hollow trunks or abandoned woodpecker holes. These natural hollows offer superior protection from rain, wind, and snow, making them a preferred choice, especially during colder months. While dreys are visible from the ground, den nests are often hidden within the tree’s structure.
Choosing Materials and Location
Squirrels strategically select nesting materials and home locations. For dreys, they gather natural elements like twigs, leaves, moss, and bark strips. Occasionally, they incorporate man-made debris such as paper or fabric for added insulation.
Den nests, being pre-existing cavities, primarily require lining materials for comfort and insulation. Drey locations are typically at least 20 feet (approximately 6 meters) above ground, often in a tree crotch for strong support. This elevated position helps protect against ground predators. Squirrels also consider proximity to food sources, selecting trees that provide nuts and seeds.
The Building Steps
The construction of a drey is a multi-step process. It begins with the squirrel weaving a foundational platform of twigs, forming a sturdy base. Damp leaves and moss are then packed onto this twig platform to reinforce the structure, adding stability and initial insulation.
A spherical frame is woven around the base, creating the drey’s outer shell. The squirrel stuffs additional leaves, moss, and twigs into this framework, forming a dense, football-sized structure.
The inner cavity, typically six to eight inches in diameter, is then lined with softer materials. This inner lining often consists of shredded bark, grass, leaves, feathers, or fur, providing warmth and comfort. Squirrels use their mouths and front paws to grip and manipulate materials, bending stiffer twigs with their heads and faces to fit them into place. They shape the inner cavity by rotating their bodies within the developing nest.
Why and When Squirrels Build
Squirrels construct nests primarily for shelter and protection throughout the year. Nests provide a safe haven from predators and harsh weather conditions. They are also crucial for raising young, offering a secure and warm environment for litters. During colder months, squirrels may share a nest to conserve body heat.
Nest building is an ongoing activity, with peak construction often coinciding with breeding seasons or in preparation for winter. Squirrels typically have two main nesting seasons annually: one from late winter to early spring, and another from late summer to early fall. Females prepare nests for their first litters born between February and April, and a second litter typically arrives in August or September.
Squirrels also build multiple nests, sometimes called “vacation homes,” which serve as emergency refuges or temporary resting spots.