i recently bought 3 rhode island pullet hens. I put them in with my flock and they are getting on very great. after a week i let them out with my old to free range which i do witih my old hens. I went up to lock them up at around 9.30 pm. They all came back and were roosting apart from one. I was worried and thought a fox got it. I locked them up anyway and in the morning there she was outside the hutch picking about. I imeediatly put it in. It has being doing this for aroud 3 nights now. how can get her to go in at night because i dont know she goes.