Newspapers Junk mail Magazines Paper Cardboard boxes (Clean) Paper bags (Clean) Plastic bottles Litter box Cat excrement ("kitty poop") in a scoop Put kitty poop in the garbage, not in the toilet Put kitty litter in a bag Use a double plastic bag for kitty litter Cardboard pizza box (dirty) Tin cans Paper plates and cups (dirty) Cardboard and paper packages (clean) Used diapers Plastic water containers Milk cartons (dirty) Cardboard egg crates Glass bottles Aluminum cans Rotten fruit and vegetables