I have 5 hens that are 15 weeks old, and 2 roosters..... 1) When can I feed the 15 week olds layer pellets? 2) Can the roosters eat layer pellets also? 3) My hens dont really like oyster shells, is that a problem? How many should they be eating a day? 4) Do bantam hens lay at about the same age of 17 weeks of adults? Thanks, I had alot of questions so I thought I'd list them out!