I am not totally new to chickens, we moved into our house in the country 2 years ago, and it came with 6 2-3 year old chickens who had a large coop and run area. That summer we let our chickens free range from late June until the snow fell without one of them dying or getting hauled off, it was great. Since then we have lost a lot of chickens and had to introduce new chickens to our flock and everything has gone reasonably well until this year. At the beginning of this spring we had 3 of our original flock, one bird who I called Lucky who was about a year old, and 2 young hens who I had introduced to the flock last year as pullets. Now this is where the trouble started, one day the 2 old barred rock hens got plucked off by a fox, I actually saw him run across our yard, but by the time I could get out the door they were both gone. Then about a week later Lucky (who was a Silver Laced Whynotte) disappeared without a trace, no feathers just gone! I was quite upset and my solution to the problem was to get 4 new barred rocks pullets. At this point in our coop we had 1 Aruicana (still from our original flock), 1 Brown Leghorn, and 1 Black Sex Link (who are about a year old). We got the barred rocks pullets when they were already 10 weeks old and we just put them into the coop with the old birds at night. They lived in the coop huddled together on the ground for a few days without incident. Then one day one of the pullets got out of the coop into the fenced in run area and my husband saw the black sex link and the brown leg horn get on top of her and start plucking feathers off her head. He was able to get her out with just a little blood and we decided to separate them until they got bigger. A few weeks passed and her head healed up and one of her pullet sisters died in the coop of something or rather and we decided it was time again to try to introduce them to the older birds. We let the big birds out to free range and left the little ones in the coop. We were around for a few hours and we saw them all walking around the yard seeming to get along just fine. Then we left for a few hours and when we came back 2 of the pullets were gone and one of them was in the run area with all the feathers plucked off her head and neck bleeding pretty badly. We got her inside isolated her and put some medication on her head, and went looking for the other birds. We were able to find them in the pucker brush and got them back into the coop in a separate area. At this point I was going to wait until the 3 got full grown and try isolating the black and brown bird when I reintroduced the pullets when the ones head healed, but then yesterday the Aruicana and the Black Sex Link also disappeared without a trace! So at this point I am left with one Brown Leghorn who is about a year old, in the large coop area with access to the run by herself. Then I have the 3 pullets next to her in the coop separated by chicken wire. The bald headed chicken is still recovering but seems to be OK. I was not going to reintroduce the young chickens to the older ones again until she was all healed but now I am afraid the one brown leghorn might be lonely. She just paces back and forth in the run by herself all day So I guess with all this information I am just looking for suggestions on what others think I should do.