So I let my chickens out of the coop to free range all day. At night they used to go back in the coop to roost and I would close them up to keep them safe. Now for the past few weeks, they elect to roose in the huge live oaks in my backyard. I literally have to catch them before they fly up or herd them in the coop now to get them in there. Anyone have any ideas why this is happening?