A porcupine is a rodent that is closely related to both mice and beavers. It is medium sized, weighing between 10 and 28 pounds and growing up to 20 inches long.
A porcupine is covered by guard hairs and quills. The majority of its coat is made up of soft hairs, but vulnerable parts of its body are protected by quills. These quills are found along the back, tail and sides of the porcupine. They are sharp and help to protect the porcupine from predators. The quills are also replaceable once they fall out. Some species have especially long quills, such as the crested porcupine. These quills grow up to 1 foot long, depending on the size of the animal.
The porcupine is a nocturnal animal that comes out mostly during the night to eat. It feeds mostly on wood with a special affinity for fir, pine, maple, beech and oak, and many species of porcupine can climb trees to reach food. Despite its nighttime habits, it has poor eyesight that is supplemented by a keen sense of smell.
A baby porcupine is called a porcupette. Although its coat is soft at birth, the quills harden within a matter of days.