I just weighed my soon-to-be-breeder rats. Creampuff, my beige male is sitting at 250g. Nutmeg, my agouti berkshire is about 215g, and Noel is around 205g. All are 12 weeks old (round about. I have no clue as to their actual ages. I guessed when I got them). So 4 more weeks and they will be old enough to breed. I can't wait! I love baby rats! What is the minimum weight a rat should be for breeding? I've heard 250g but I want to be sure.