I have 12 8 week old chicks that I think are too skinny. I work 12 hour shifts and I let them out of the run to free range in my yard before I go to work and lock the run at night when I come home. When I close them up at night I always pick some of them up and check them over to see how they are doing. Well, it seems to me when I check them at night, their crops are almost empty (this is 8:30 at night). I have chick starter crumbles in a round metal hanging feeder that I keep filled every day, I check it morning and night and make sure it is filled and dispensing the feed correctly, I give them treats such as bread, grapes, scraps, etc on my days off, but they just seem skinny to me! I know they are adolescents and are still growing, but...They seem very healthy, bright eyes, very active, feathers are shiny, etc but they feel skinny to me! They have access to their feed all day, is there something else I can feed them to put a little weight on them, or is this normal at this stage of their life?