I have an approximately 3 year old Americana hen that we have had for about 6 months. She will not get off the nest at all. she was very active for the first 4 months, then we noticed that she was in the nest a lot. We check and found that she was laying on a few eggs that we took from her. Since then she will not leave the nesting box. I will take her out and put her on the ground only for her to go right back to the box. Any thoughts ?