We had a flighty young cat, newly rescued, we had locked her in a bathroom downstairs and were trying to get her acclimatized with using the little down there and such.

She went all david copperfield. POOF gone. Searched the whole bathroom/launcry combo. Nothing. There was a ceiling tile out... we searched the whole cleiling of the entire basement. nothing.

back to the bathroom, pulled the washer, the dryer, not hide nor hair.

I poked around, and back behind one of the cabinets, it didn't fit right to the wall, she had climbed in back there.

we replayed that in a new house 12 years later, when I had a central heating duct in the bedroom out to try to install a supplimental blower. that took 2 days and some food to get her out.