Hello, how long have you had little Enzo for? Sometimes newer hamsters have a tendency to nibble as they've not yet learned manners around humans. Hamsters aren't like us in that we see with our eyes, they see with their noses and whiskers. They also will use their mouths to explore as they have not been blessed with opposable thumbs as we have. The unfortunate part of this is that being nibbled can hurt! Something I've done with particularly bitey hamsters is used a treat reward system whenever they didn't bite. I'd offer my hand and if they sniffed or ignored it, they received a treat. If they bit or nibbled, I would push them away gently and not reward them. I repeated this process until they eventually caught on that biting was not acceptable. Good luck