<human>:  Can you tell me difference between a porcupine and a hedgehog?
<bot>: A porcupine is much larger than a hedgehog. Porcupines have longer bodies and larger heads compared to hedgehogs. They also have protective spines that cover their body and can be raised when the porcupine feels threatened. Hedgehogs are smaller than porcupines with rounded bodies covered in short spines. They also curl up into a tight ball as a defense mechanism.