Why do porcupines have quills?
For grown-ups: the science
Porcupines have sharp quills, which are special hairs that help protect them from animals that get too close.
Porcupine quills are modified hairs made largely of keratin. They are defensive structures: when threatened, porcupines raise them and may back into an attacker. Porcupines cannot throw or shoot quills; quills detach on contact and are replaced over time.
What about...?
Ask your child's own question
Transcript
Look at that porcupine walking through the grass, with its pointy coat! Why does it have quills?
A porcupine’s quills are stiff, sharp hairs covering much of its body. They help protect it from animals that might try to bite it.
When a porcupine feels threatened, it lifts and points its quills outward. The sharp quills can poke an animal that gets too close.
Porcupines do not shoot their quills. Quills can come loose when they touch another animal, and new ones grow back.
So, porcupines have quills to help keep their bodies safe. Their pointy coat tells other animals to give them space!