Cats throwing up. Yarking is what we call it about here. There is an exact protocol to follow. First, you must yark the nastiest load on the most expensive sofa/chair or rug in the house. Then you must move down the the next level, hardwood floors, tile floors - hide those a bit so the flavor has chance to soak it real good. If a human tries to put a cloth in front of you, give it your best yark show and at the last second, turn your head and yark one inch off the cloth. Extra points for yark they don't find until barefoot coming down the hall one dark and creepy night.
Thor sez: This is not amusing.
Thor sez: Really, I don't talk about your private foibles.
Thor sez: Hmmph. You don't know the half of it. Yarks you never even see. Until I want you to.