Why? It’s a discreet and effective way to check if anything or anyone is hiding beneath.

If the bottle rolls freely across to the other side, the space is likely clear. If it stops or gets blocked, it could be a warning sign. In such cases, you should leave the room immediately and alert hotel staff or security to investigate further.

The idea is to stay cautious without putting yourself in a vulnerable position. Bending down to manually check under the bed could expose you to danger if someone is hiding there.