Our rat rent was purchased young and was a pretty mellow guy. We've handled him regularly since we got him (he was probably about a month old) we have an old rat who is around a year old that we introduced him to and there were no issues for several months. About 2 weeks ago remy (the younger one) started picking on Rocky (the older one). Rocky is an extremely gentle rat and just takes it. Well after having to separate them several times and it not getting better I now have them in separate cages. Rocky is almost mentally scarred from it now and we are nursing him back from it. There was never any blood (except bit ears on Rocky) so I'm not sure it was aggression but it got so bad remy was stealing his food from him and Rocky is very shy now and seems depressed. I want to reintroduce remy with Rocky but this can't continue or Rocky with have lasting damage. Anyone have any suggestions?