Okay. So my rat, Sparrow, is really old. 2 and a half. I've got four rats now. 2 five months old. And one 3 month. Well I got Orville at 2 months a month ago. Kept him in his own cage until last week. He's a real sweet boy. And my other two boys have no problem with him. But my old mam Sparrow has been trying to be dominant over him as he can't be dominant over my other boys. Today, Orville really put him in his place and tore his ear clean in half. Its a bloody mess. But he doesn't seem in pain or anything. And Orville is smaller than him. Why couldn't he defend himself? I'm all the years of having rats this has never happened to me. What should I do? My old man isy heart rat, my special boy. And he's so old and has congestive heart failure I don't want him to die any earlier than he already will. Please give me advice...