One of our hens has recently taken up sleeping at nights in one of the nest boxes. We only have 2 hens, one sleeps on the roost but this hen has never been able to get up onto the roost so she sleeps on a lower roost. We had a few weeks of cold weather and that is when she started sleeping in the outside attached nest box. Head first into the box. Of course she started pooping in the box which meant that I had to clean the bedding in the nest more often. Last week I removed the plastic container and closed off her favorite box. Tonight she was using the second box to sleep in. How can I stop her from doing this? Build a ramp for her to use to get up to the upper roost?