Cat food puzzles
Do you have a cat? Does it pee or bite what you don't want it to?
Research suggests your cat might be frustrated with its life, since it is semi-domesticated after all. Especially if it is not allowed out, it might be a good idea to enrich its environment.
The catch is you might need to collect some more food pieces from around the house than you are used to.
Here is the easy read version with more information, and here is a specialised site which inludes instructions on making homemade cat puzzles. It looks like a fun weekend project regarldess of outcome.