Well first of all, it isn't right regardless. But to answer your question, they can eat it and it could do damage to their intestinal tract by causing a blockage. Then they would die a slow and painful death. They can get tangled in some trash. The plastic that holds sodas together,strings,ribbons,etc can get tangled around legs,wings and necks that can cause strangulation,slow amputations(with infections), etc.Some animals can't vomit and can't expell the litter. Hope this helps