So harry and schnitzel are half brothers and have been together pretty much since they were 5 weeks old and they were bred by a local breeder and had a home until they were just sylhy of a year old in march which is when we got them because the families kid became allergic but I don't think that was an actually reason because when we got them I noticed harry had a lot of old and new wounds which I didn't know how they got there until hours after we got them I had to pull schnitzel off of poor harry and even though we have tried our best to get schnitzel to stop his aggression towards his today was the last straw for me. He attacked harry and would not stop and I actually had to pull harry out from under him because every time I pushed him off he came right back and almost bit clean through Harry's tummy so now I have to try and put harry with our newest boy which I have introduced them a couple of times however because of his brother he is terrified of other rats.. How do I get him to see that not all rats are mean like his brother?