I like my house really, really cold. When my bunnies sleep, if I have the "ice conditioner" on at my prefered setting, they sleep in a cat bed or ferret bed. They use it for their hide-out too. I found the flat ones (round with about a 1" roll around it) clearanced at ***co for $1 each. I bought all they had. My "very small wild bunny" Gizmo, sleeps in round furry circle with sides about 3 or 4 inches high. When he flattens out, you cannot see him unless you go and look in from the top. My mini-rex, Gypsy, is about twice his size. She likes a "cat-cube." It has smooth cotton on the outside and fake fleece on the inside. In both cases, the move them around the cage daily. Both of them turn them over if and sleep on them as a "pad" when my husband goes on a rant about the electric bill. But both bunnies use their bed every day!