This large rodent can use its ever growing incisors to fell more than 200 trees a year, creating mosaics of dams, lodges, and canals. Building is a constant instinct; after a pond has been dammed deep enough that it won’t freeze to the bottom, a beaver colony will still keep working. They’ve even been seen trying to reinforce concrete dams with sticks. Over time, the animal can transform woodlands into wetlands, and ultimately into fertile meadows.
 BODY The average beaver weighs about 60 pounds. When using a body-grip trap to remove nuisance beaver, avoid catching other animals by moving the trap’s trigger to one side, shortening the length of the wires to 4 or 5 inches, and bending them close together. Otter and mink will glide through the square, but bulkier beaver will likely trip the trigger.
 MOUTH A beaver has an extra set of lips that seal behind its front teeth, allowing it to eat beneath the surface without swallowing water. If a beaver’s pond ices over, its winter diet consists entirely of wood cached beneath the surface. This leaves the animal craving fresher fare. To trap one, tie green twigs of aspen or poplar to a pole, and attach a body-grip trap on top of them. Cut a hole in the ice and push the pole into the mud at the bottom.
 FUR Pelts are prime in midwinter, when the animal’s coat is thickest. Beaver are the only furbearers that are “open skinned,” meaning that you cut down the belly and peel the skin away from the body, creating an oval rather than a sock shape. These pelts make interesting wall hangings for a hunting cabin; form a hoop from a sapling and stretch the skin inside by sewing it to the wood with rawhide.