The other night I was home alone. The middle of the night the bed shook and I heard a noise. My big shepherd does this routinely. I thought it was him. I got up and there was nobody in the room with me. I turned the light on and he was not in the room with me. He was laying on what we call the dog bed. ( A bed we have in a spare bedroom). He raised his head and looked at me, so I know it wasn't him. Not sure what shook the bed and made a noise.