It lives in forests and often can be seen hunched into what appears to be a black ball high in a tree. While it doesn't occur in all parts of Pennsylvania, the porcupine is one of our best-known and most easily identified wild animals. Its taxonomic name is Erethizon dorsatum . They live at all elevations from sea level to timberline. They weigh 9-15 pounds, with bigger, older adults weighing up to 20.
Males are larger than females.
Short-legged and stout of body, a porcupine has a pronounced arch to its back. The front and back feet bear long, curved claws, and the soles of the hind limbs are thick-skinned and callused. The tail is short and club-shaped. The summer sun bleaches the guard hairs of some porkies, giving them a grizzled appearance. Albinism sometimes occurs.