The North American porcupine waddles through the forests of North America. It sleeps during the day and is active at night, when it feeds on tender branches. Most animals its size have to be wary of predators, but the porcupine is well armed. Most of its body is covered by sharp, stiff quills. Any predator interested in a porcupine meal has to find a way to reach its unprotected belly. The porcupine can drive its quills deep into an enemy's skin. Animals that have encountered a porcupine's quills know to stay away.