My chinchilla?????????

He's fine. He's just getting used to his new surroundings. That a big change for him, so he's probably both stressed and curious. He should fall back into his nocturnal routine in a few days. If not, the person who had him before you may have had him up during the day and he may have became diurnal, though I'm guessing this is highly unlikely. Just be sure that he's got a safe and quiet place during the day. If the room is too noisy, it may be keeping him up. Good luck!