A hopper separates waste from cat litter. The hopper may include sidewalls with a top and a bottom. The sidewalls may taper from the top to the bottom. At the bottom of the hopper is a grate. The hopper may be placed on a pail and the cat litter and waste may be poured directly into the hopper. The clean cat litter may pass through the grate and the waste may be caught on the grate and separated from the clean cat littler.