They are a unique, yet common resident of the coniferous forests of the western and northern United States. Unfortunately, they feed on trees and agricultural crops, chew on wooden structures, vehicle tires, and hoses, and menace animals and humans that disturb them. It's quills provide a very effective defense system. Rather, the quills are loosely attached and easily dislodged when the flailing tail makes contact with an enemy. Porcupines have poor eyesight, but a well-developed sense of smell and hearing, allowing them to easily detect faint sounds such as footsteps and rustling leaves.
Porcupines are generally solitary animals, and are strongly attached to a territory.
Territory sizes vary and can be up to several hundred acres throughout the summer months. During winter, this territory shrinks considerably, usually down to six acres or so. The female generally has one offspring per year in May or June. Porcupine diets vary with the seasons and differing habitats. Porcupines feed on herbaceous vegetation in the spring.