Hi, I have a sand run and I need a slightly warmer option for my girls as it's only going to get colder here in Wisconsin. I'm about to put pine shavings in the hen house for warmth at night and I want to know what I could do to keep their feet warm when they are out in the enclosed run. I was thinking maybe hay or alfalfa bales to put in the corner where they like to hang out and get warm when they aren't eating. My run is about about 10'x6' so it's a fairly big area to cover if I was to do the entire space. What do you suggest?