Sorry, I have a ton of questions about this. I'm building my first chicken tractor and I've read that some folks use some sort of wire mesh for the flooring under the roosts. Can I use some of the hardware cloth I was planning to use to enclose my run? Will it get too cold in the winter (Portland, OR) with a open floor like that? Will I still need some sort of vents at the top of the house too? Thanks!