I did some searching and found this info from a large Mousery that had alot of problems with lice and mites. It seemed to work for them and if it was safe for a mouse wouldn't it be for a Rat? scroll down until you get to lice/mite treatment. Spider
WWW.thefunmouse.com/info/hair-loss.cfn
WWW.thefunmouse.com/info/hair-loss.cfn