In various stages of Ritz's latter kittenhood, she had this annoying habit of chewing on parts of the DRYWALL. We found one or two places where she had torn the facing of the sheetrock paper off and then obsessed over the spot until they were rather unsightly holes. We covered these temporarily with cardboard and eventually took them away---no instances since.

She also likes to "crawl upside down" under the sofa...this must be some kitty fantasy that represents the closest they can come to walking on the ceiling.