Hi! M RIRs are over a month old but they are much smaller than my other chickens. I have Australorps, Barred Rocks, and RIRs and the others are so much bigger. (Aren't Barred Rocks supposed to be a smaller breed? Because they are huge!) Is this a problem that they are smaller than the others even though they are the same age? They are all really sweet with each other so I am not worried that the others will bully my RIRs. I was just wondering if they need some supplements or something. Any suggestions? Thanks!