Rodents, including beavers, must keep gnawing because their teeth keep growing longer and must be worn down. This works well to keep them sharp: Their teeth have a gradient of hardness from the hard front to the softer rear, so as they wear down, they self-sharpen.
Rodents, including beavers, must keep gnawing because their teeth keep growing longer and must be worn down. This works well to keep them sharp: Their teeth have a gradient of hardness from the hard front to the softer rear, so as they wear down, they self-sharpen.