Squirrels are a common sight, often observed gnawing on various wooden objects, from tree branches to backyard fences. This persistent behavior stems from both physiological necessity and environmental factors, helping these agile rodents survive and thrive.
Continuously Growing Teeth
Squirrels, like all rodents, possess incisor teeth that grow continuously throughout their lives. These four front teeth can grow approximately 6 inches per year. Gnawing is essential to keep these incisors at a manageable length and maintain their sharp, chisel-like edge. Without constant gnawing, a squirrel’s teeth could become overgrown, leading to malocclusion, where they do not align properly.
Overgrown teeth can hinder a squirrel’s ability to eat, causing severe pain, and in extreme cases, may even grow into their jaws or skull, resulting in starvation. The front surface of their incisors is covered with hard, orange-tinted enamel, which wears down slower than the softer dentin on the back. This differential wear creates a self-sharpening mechanism, maintaining the teeth’s effectiveness for breaking down tough materials. Therefore, gnawing serves as a fundamental dental hygiene practice for squirrels, enabling them to process their natural diet of nuts and seeds.
Seeking Nutrients and Other Motivations
Beyond dental maintenance, squirrels gnaw on wood for several other reasons, including seeking nutrients. They often target the cambium layer, a moist, nutrient-rich tissue found directly beneath the outer bark of trees. This layer contains sugars and other essential minerals, providing a valuable food source, particularly when nuts and seeds are scarce, such as in late winter and early spring.
Gnawing can also be an exploratory behavior, allowing squirrels to investigate their environment and potential food sources or nesting sites. They might chew wood to gather fibers for nest construction, creating soft lining for their dreys, which are their nests. Additionally, some gnawing may serve as a form of territorial marking, as squirrels can leave behind scent through glandular secretions while chewing.
Common Targets of Gnawing
Squirrels exhibit their gnawing behavior on a variety of wooden objects, both in natural environments and human-modified landscapes. In natural settings, they frequently chew on tree branches and bark. They often prefer younger trees or branches with smoother, thinner bark to access the cambium layer more easily.
In residential areas, squirrels commonly gnaw on wooden fences, deck railings, and outdoor furniture. They also target wooden components of homes, such as siding, fascia, and roof trim, especially if the wood is weathered or provides easy access to potential entry points. This behavior, while natural for squirrels, can lead to noticeable damage on various wooden structures.