How did porcupines get there quills?

Porcupines have quills as a defense mechanism against predators. These sharp, barbed quills are modified hairs made of keratin, and they evolved over time to help protect the porcupine from attacks. When threatened, porcupines can raise their quills and, if contact occurs, the quills can easily detach and embed in the skin of predators, causing pain and injury. This adaptation has helped them survive in various environments.