Hi friends. We don't currently have a good set up for our girls to dust bathe in. Although they love the small pan I provide them, it only accommodates one hen at a time, and when she's done, the dirt is usually gone. I'm considering closing in the back end (under the raised house part) by putting up siding on the outside of the back and sides, leaving the inside under the coop open and just placing a 2x6" to hold it all in. Enclosing it will ensure it stays dry, since I use a mixture of ash and dirt. I'd access it by putting a drop down door on the outer backside so that I can add to and rake out without having to crawl inside the run. My question is, do you think ventilation will be an issue in there? It'll probably work out to be 2 1/2' tall, enclosed on 3 sides and top. I could drill some small holes in the back drop door and even the sides, then cover with hardware mesh? Small enough to let air flow through, but not let lots of rain in? Here's a pic of my coop/run if anyone has any other suggestions. We just finished a large outdoor run for them, as well.