The New World porcupines, family Erethizontidae, are large arboreal rodents, distinguished by their spiny coverings from which they take their name. They inhabit forests and wooded regions across North America, and into northern South America. Although both the New World and Old World porcupine families belong to the Hystricognathi branch of the vast order Rodentia, they are quite different and are not closely related.

Rodents are mammals of the order Rodentia, which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are native to all major land masses except for New Zealand, Antarctica, and several oceanic islands, though they have subsequently been introduced to most of these land masses by human activity.