Piece of fleece over the wood pellets. The fleece muffle the noise and create a softer surface, while wicking urine through the very absorbent pellets. Twice a day, I simply roll up the fleece, take it outside, shake off the poops and hay, and lay it back down all nice and clean. The cage is completely odor-free, even though I haven't changed the wood pellets for a full 3 weeks.
Make this doughnut bed for you guinea pigs. Easy DIY with step by step instructions and pictures. I'm making one for my hedgehog to put under his igloo so he can be comfy, cozy and safe at the same time!