My chick's are going to go in with my hens that just started laying in about 4 to 6 weeks. The thing that concerns me is they eat two different kinds of food. The chicks eat starter/grower until they reach 18 or so weeks. The others are eating layer crumbles. How do I make sure they get the food that is meant for them while they are all free in the coop? I'm not able to separate them. Thanks