We had two lovely windy brown chickens, about six months old. Sadly one just keeled over and died. After a week or so we have replaced her with a new one. We have introduced them slowly, given them space etc. but the older one simply will not let the other out the coop. Any sign of her venturing out and is viciously attacked! The new one will now not even venture out the nest box! Any ideas? I know ideally we should have got more than one extra, but a little limited on space so don't want them overcrowded.