I just got home from work and found 1 of my BO hens in the run, Dead! I felt her crop and checked her for prolapse and egg binding, and Nothing! What could have killed her and not left a mark? All were fine this morning when I went to work. I open the pop-hole door before I leave and it is still dark now. Any ideas? I also have a kitten missing, so I'm thinking I have some sort of predator around.