The sudden sound of the hotel after lights out doesn't sound like footsteps.

1. Problems of the building itself: due to structural problems of the building, such as the vibration sound generated by water pipes and heating pipes.

2. Air conditioning system problem: the hotel room has air conditioning, which may be the vibration sound caused by the air conditioning system problem.

3. Influence of surrounding environment: B&B hotel is located in or near a busy area, which will produce noise such as construction or machine operation, which is caused by the influence of surrounding environment.