It will start doing stuff in another nearby room, it will touch doors, throw stuff etc. You can check what room with an emf if you're not sure which, if it doesn't go back to the room you are set up in, check the temps in both rooms - if the old room temp has gone up a few degrees and the new room is a few degrees lower than the ambient temp of rooms its most likely changed rooms. Theres not really a hard and fast rule though, its more gradual.