I have a 6 month old buff Orpington that has been sitting in the nesting box for over a week, why is she doing this? She was a runt out of the 9 chicks, but she finally layed a very tiny egg a week ago and nothing since then. I have taken her out and she is usually back in the nesting bow within about 20 minutes. Is she sick, or what? Any suggestions would be appreciated. Thanks!