I came home from work just a while ago. I went out to lock up the chooks. When I counted I knew 1 was missing. I noticed the BO hen was not there. So I walked over the back yard. I found no feathers and no hen. I looked down the back alley and as far as I could see with a mini mag light and no feathers. I have an 8 x 20 run with 8 x 8 covered south side covered. I was leaving them locked up on days I worked. About 2 months ago I started leaving the gate propped open so they could go in and out. I felt like it was best for them to free range and lock them up when I come home. I think of 2 things that may have happened. She could have flew out and then a dog may have got her. Or shes hiding because I think she was maybe going broody and I kept getting the eggs. I now think its best to keep them locked up when I am not home.