So today I found my poor rat Volos had passed away at 11 weeks old. His brother Vodnik is doing well, so far. I noticed it a week ago, Volos was hunched and when I went to go pick him up he felt thin, skinny and light compaired to his much bigger brother. I don't have the money right now, but has anyone experianced one cage mate dying and having to get another?. If so when, and how old should the new male rat be. Vodnik and Volos came from the same litter, they were legit brothers, so not sure how he'll take to a rat not really being his "real" brother, and I'm worried about his age with introducing this new rat. Or should I just give Vodnik away to the humane society here in Ottawa, I'm very worried and sad about this getting a new rat won't work.