Hang a Pet to Be Alone

Bér the Hanging Dog
A creative “do not disturb” door sign at the La Bergère Design Hotel in Maastricht, the Netherlands. The next step could be hanging small live animals on a doorknob?
This is by far not the only trick they play in that place to justify the “design” part of the name. However, randomized door numbering on a floor can get quite annoying if you are really tired and would prefer to actually find your room.