Maybe we can round up a few more concerned rat moms/dads and get someone to produce Biggest Loser - Rat Edition?
I'm concerned about such a big drop in less than a week. Hopefully nothing serious is going on with him. One of the saddest things about his weight is that he has trouble itching spots like behind his ear, etc. I have caught him trying before, frantic and squeaking those frustration pain/extreme itch squeaks and falling over because he can't reach. So sad, I'd always go over and scratch for him, but I can't be here all day to do that. Today he got his back leg up and, with some effort, was able to scratch his cheek.