I put granite grit in a shallow dish and oyster shells in another, which are next to their feeder in the coop. They just get what they want. Mine do free range but it is very fine sand here, so I'm not sure if they are getting what they need, so I keep it always available for them. The baby's I offer it to them but instead of buying chick grit I smash it to make it finer and have had no problems so far.