Ok thanks for suggestions. My neighbor thought he had seen a possum around but I've set traps and put moth balls under she'd next to the coop but have come up empty. I've checked for mites and other pests as well. I'm pretty much a stickler for keeping coop clean.
New to chickens pretty much. Have hens approximately 4 years old who decided they would rather roost in trees at night instead of returning to coop. They haven't started doing this until a couple of months ago. Now they rarely go back to it even with their food and water there . Any suggestions...