Hi Kayjay, I use newspaper and hay and I usually put the heatpad under a huge pile of hay. The buns are very good and the heatpad cover stays dry, as they tend to wee elsewhere in the hutch. If your piggy is less fussy about where he goes to the loo, putting under the newspaper may be better or try wrapping the heatpad and its cover in an old towel and then put this under the hay. You are going to have one happy piggy/piggies!