I have 6 laying hens and three 3 month olds. They are now relatively happily living together but I'm not sure how to keep their food separate. I had run out of grower crumbles and they were eating the layer food for a little while and now I've run out of the layer feed and wonder if they all can eat the crumbles? I have oyster shells but how do I keep the younger ones away from it? I can buy the layer feed, but just am not sure how to feed them separately when they are living together.