I had been using straw for the coop floor and nest boxes. However this winter, with the girls staying inside more, the smell was getting bad. I figured this wasn't good for them, or us. Cleaned out all the straw and put a 4 inch layer of pine shavings down. What a difference! Smells way better, and they were happier too. With their scratching, the poo gets pushed down, and have a nice clean coop. I have read some people only clean out the shaving once a year, and have great compost. We will probably do it more often. This does seem like the way to go in the winter.