Erethizon is a genus of rodents commonly known as porcupines. These animals are primarily found in North America and are recognized for their distinctive quills, which serve as a defense mechanism against predators. Porcupines are mostly nocturnal and are herbivorous, feeding on leaves, bark, and fruits. Erethizon species are typically solitary, although they may be seen in small groups during mating season. They have strong, curved claws that help them climb trees, where they often reside. Their quills are modified hairs coated with keratin, making them sharp and effective for protection.