|Beaver gnawed off Birch Tree. A beaver chew is undeniable evidence of beaver activity in the area. More can be found along the canal. Beavers chew on trees for a number of reasons. They make their lodges and dams from the saplings. They eat the inner bark (sapwood) and will store fresh cuttings underwater for a winter food source. They will cut down undesirable trees like pines and spruces to allow more preferred trees like aspens and poplars to grow. Lastly, they chew wood to wear down their teeth, which never stop growing. If it was not for the constant chewing of hardwood, their teeth would prevent them from eating, as is also the case with other rodents.