We have 15 chickens that we purchased at the end of March. We have 15 more that we purchased mid-May. They are very close in size by comparison. While they share the same living space, we had them blocked apart and their yard was also segregated with fencing - they have had this arrangement for about 2 months. We are trying to integrate them - today is the first day. The roosters from the older hen flock will not let the younger hens come out into the yard. Can we do anything to help the situation or to help them get along?