it's a good thing that the vet didn't find anything medically wrong with him...now you need to play detective...get on your hands and knees and literally follow him around...he may be rubbing on something...one of his cage mates may be doing this...it could be anything...but you'd be surprised the contortionists they are...this could be something very simple... i had a ferret that kept getting sores on his hip, just one... after alot of tests, i found out that he used the bottom of my couch to rub against almost like a bear with a tree...once they lose the fur, it itches when it has to grow back in, then they rub or scratch more, hence the cycle begins!! you can actually put a bit of lipstick on the spots to see where it ends up...a bit won't hurt them, but will tell you quickly who's nose it's on, (or not), or what object,,,..but check everything!! good luck, let us know! [Posted in FML 5442]