Squirrels chew on wood primarily for two main reasons: dental maintenance and gathering nest material.
1. Wearing Down Their Teeth
Squirrels are rodents, which means their front teeth (incisors) continuously grow throughout their entire lives—at a rate of several inches per year. If they don't constantly grind them down, their teeth can grow too long, making it impossible for them to eat. Chewing on dense materials like hard woods, tree bark, and branches provides the friction necessary to file their teeth down and keep them sharp.
2. Nest Building and Insulation
In addition to filing their teeth, squirrels often chew away strips of wood, bark, or wood fiber to harvest soft materials for building their nests (drey). They shred the fibers to line the inside of their nests for warmth and cushioning.
Other Reasons
Minerals and Salt: Sometimes wood (especially processed timber, outdoor decks, or furniture) contains absorbed salts, minerals, or chemical treatments that squirrels are attracted to.
Scent Marking: Squirrels have scent glands near their cheeks and mouths. Chewing or rubbing their faces on wood helps mark their territory to inform other squirrels in the area.
