I have tried looking through the archived posts and can't find the answer to this, althout I am sure its out there. I am wondering if Oyster Shell does the same thing for the crop as grit does? I was told this, and have never fed my girls grit... Do I need to feed grit AND oyster shell? Thanks so much for your help. Also.. will it hurt the 10 week old chicks to have access to the oyster shell? Thanks!