I bought my first hamster a couple weeks ago and everything was fine. But now whenever he sees me he runs towards the bars of his cage and starts biting very aggressively? Or enthusiastically? Im not very sure, plus he tries to bite if i try to touch him or even put ny hand inside his cage. What can i do so he can be comfortable with me? I noticed he reacts to his name so thats a plus, but other than that no progress.