I use both. My two don't sleep in the "sleeping area" (they use it as their bathroom) so instead I've made them a snug in another part of the hutch where I've pile in a load of straw. I then place a layer of hay on top which they love to munch on and in the hope they don't eat the straw. When I do a clean out, there's never any mess in the snug and all the hay is usually gone. Daisy sometimes like to pull the hay from their litter tray in the "bathroom" and puts it in the snug. I can hear her digging and pulling at the hay from the litter tray, she loves "rearranging" the furniture in the hutch.