I change the paper in my birds' cages twice a week, or once. I don't need to do it too much because they are never in cage. Sometimes, they even sleep out of their cage, so it doesn't get dirty fast enough. I wash their cage well every 2 week. My bunnys box gets scooped everyday, and washed 2 times in a week. My goat lives on the roof. I wash the roof everyday.