That little Potato. We really have to be careful what we put near the cage, because if he can reach a paper or plastic bag, he will definitely try to eat through it. It's very bad for him, so we try to be careful, but sometimes a bag gets knocked over and lands within reach.
I think it's just hit tooth-sharpening instinct kicking in, which is actually a good thing when he's gnawing on the chew toys we give him. Which is rarely.