We have a flock of 2 year olds and a new flock of 6 chickens. They are all staying out in the coop together. We have a fenced in yard (with a 6 foot high fence) but have a few areas where there may be some space underneath for a sneak out. Usually at dark, all the chickens are in the run area or hen house and are settling in for the night. Tonight, we went out to check on them and we are missing 1. We don't even know how long she's been gone. We have wooded areas all behind us. With neighbors on both sides in a residential area. Does anyone know what their instincts will tell them? Do they perch up in trees or will she bed down and hide? We searched the area as best we could, but no luck. She was not in their normal hiding areas.