We got 5 chicks a while back and love them. About a week ago we decided that 5 werent going to produce enough eggs for my family, so we got 7 more. The problem is there is about a 9 week gap in age. I am keeping them separate right now. My question is how close in size do they have to be until I can put them in the same run? The older chicks are 10 weeks and the younger chicks are 1 week old.