Right now its about 50-50 in the litter box and on the fleece on the bottom floor. They rarely pee or poop on the fleece on the second floor. It smells bad and I don't want to have to clean the fleece as much since its easier to clean the litter pan. I already have a stone in there cause they like peeing on rocks ? Is there anything else I can do to make them pee and poop in the litter box more?