I have nine of the finest free-ranging Rhode Island Reds a girl could want. They lay well and peck and scratch close by the house or their coop. We have almost four acres of open space in the back yard. TODAY, seven of the hens decided to leave their normal areas and head all the way in the far back yard completely out of site and did not come when they were called. Why would they do this? We have food, plenty of security, water, etc.