However, an irate porcupine can swing its heavy tail with surprising quickness and if the tail makes contact with the adversary it will leave behind a dose of quills. The quills, once imbedded, absorb moisture and the barbs on the tips enable them to work their way inward with the aid of muscle contractions, as fast as an inch a day. They can be fatal if they penetrate vital organs. The quills have another use besides what the porcupine uses them for, however. Native Americans used them to create all sorts of artwork, decorations and jewelry, often dyeing them lovely colors.
Porcupines prefer mixed hardwood and evergreen forests and are mainly nocturnal.
During the day they hide in trees or dens. They have little to fear from most predators and are quite nearsighted as well as mild-tempered. This combination makes them rather friendly animals. They have good hearing and sense of smell, and are sensitive to vibrations. They fall prey mainly to fishers, lynx, fires and automobiles, and occasionally to respiratory disease.