I use straw only because I can lift it to provide air pockets and they love to snuggle down in it...sometimes I go in there and all you can see is their headsthank you for insulation info, does straw hold more heat then wood shavings? i have 8 chickens, 4 barred rocks and 4 ameruacanas. our coop is 8 x 8 and have trees and a small pond around it.