welcome to HC! Like Serendipity7000 said, he might be a little bit cage territorial or can possibly smell food on your hands. On the topic of hamster balls, there has been studies shown that hamsters get very stressed while rolling in them. their eyesight is already bad and the ball doesnt help, when you see them rolling around speedily its easy to presume that they are enjoying running around even when they aren't. They have no control on when they can eat or rest or drink. So i would advise you not to use them unless you use it to transport oreo around. its a safe way to handle him if he's nippy. instead of letting oreo run around in the ball, you should opt for free ranging by hamster proofing a room in your house and letting your hamster run freely on the ground or you can put a plush blanket on the bottom of your bathtub and let oreo run around in there. Im very excited to see more of you and oreo on the forum!
