I used to let our cats up in the attic to play in the big old house we rented in CT. One of them, Charlie, loved going under the floorboards and waltzing all over the place, so we got used to hearing "something" in the attic. It got really interesting when none of us let him up there, yet the door latch was very obviously undone and the door open. For that, and other reasons, we figured the place was haunted. Used to take a can of fishie to get Charlie to come out for the night.:-)