Squirrels construct specialized shelters, often observed high in trees, that serve as homes for protection, warmth, and raising young. Understanding the appearance and location of these nests offers insights into the adaptable behaviors of these agile creatures.
Two Main Types of Squirrel Nests
Squirrels construct two main types of nests: dreys and dens. A drey is an external, visible nest, typically a large, spherical mass found within tree branches, built from various natural materials. In contrast, a den is an internal nest located within an enclosed space, such as a tree cavity or pre-existing hollow. Squirrels may use both dreys and dens depending on environmental conditions, resource availability, and seasonal needs. Dens generally offer superior insulation and protection from harsh weather conditions.
Distinctive Features and Construction
Dreys
Dreys, or leaf nests, are typically spherical or oval, around the size of a football (approximately 30 centimeters or 12 inches in diameter). The outer layer consists of interwoven twigs and leafy branches, giving it a messy or scraggly appearance. Squirrels often harvest green branches, allowing the leaves to remain attached for insulation even after browning.
The interior is lined with finer, softer materials like moss, grass, shredded bark, pine needles, fur, or feathers. There is typically one main entrance hole, often positioned towards the tree trunk for rain protection, and sometimes a second escape hole. Summer dreys might be flatter and less insulated than robust winter dreys, which are designed for maximum warmth.
Dens
Dens are internal nests within a chosen cavity. Squirrels line these cavities with soft bedding materials, similar to those used in dreys, such as shredded bark, leaves, moss, and fur. These linings provide insulation and comfort, particularly during colder months or for raising young. If using a pre-existing hole, such as one made by a woodpecker, squirrels may gnaw at the entrance to widen it for their needs.
Typical Locations and Identification Tips
Typical Locations
Dreys are predominantly situated high in trees, often built in the forks of branches or tight against the main trunk for stability and support. These external nests are usually at least six meters (20 feet) above the ground, offering protection from ground predators. Dens are typically located within natural tree cavities, hollow logs, or abandoned woodpecker holes. Squirrels may also utilize human structures, finding refuge in attics, wall voids, or chimneys, especially during colder seasons.
Identification Tips
Distinguishing a squirrel nest from a bird nest requires observing several features. Squirrel dreys are larger than most bird nests, often incorporating many leaves woven into their structure, which birds typically do not. Squirrel nests are usually enclosed and spherical, while many bird nests have an open, cup-like shape. Dreys are also typically closer to the tree trunk than bird nests, which can be further out on branches or closer to the ground.
Signs of squirrel activity near a nest include chewed pine cones resembling apple cores, scratch marks on tree bark, and chattering sounds. Inside human dwellings, signs like scampering noises, droppings, gnaw marks on wood or wires, and displaced insulation can indicate a squirrel den.