In Animals With Spines, evolutionary biologist Ben Garrod presents porcupines and how their quills have evolved as a defense mechanism. Learn how these animals, with their distinctive spines and quills, have adapted to survive in the wild as you discover how porcupines’ quills have evolved to detach and protect them from predators. This video is excerpted from Secrets of Skin, a documentary series exploring the natural history of the body’s largest organ.