A quick post to relate a less expensive alternative to plexiglass under the door. I was absolutely desparate to stop the digging, becuase of the possibility of mean downstairs apartment people complaining about the noise. (I'm not supposed to have animals.) One night I put a big disposable aluminum cookie sheet under the door. I had to laugh because big fat puddy would dig away, and suddenly stop. He would stop and start, then off to play somewhere else. I think his little paws were getting overheated from the friction. Thank God they ALL hate the aluminum and have not pooped or scratched at the door since. Phew. [Posted in FML issue 1698]