I want to buy 25 new chick hens and I'm not sure when to put them in with the mature birds.(all hens) The mature hens are 13 months old and they have stopped laying. But I also have a pecking problem with the mature hens. There are a few that are pecking the eggs before I can get up there to take the eggs out. Out of 20 hens, I was harvesting about 12 eggs a day. Now because of a virus(which is being treated with antibiotics) they seem to be looking better, but egg production is still off. Any suggestions on the pecking of eggs and when to introduce new laying stock?