Mice in the attic ?

I was upstairs with Cooper and Otis. The electrician was working downstairs. All of a sudden Oti raced to the upstairs crawl space door and began to paw at the door. Oti then cocked his ears and began to paw at the carpet under the radiator.

My first thought was, are there mice in the crawl space ???

I listened closely and heard what Oti did - electrical wire was being threaded thru the wall. The scratching noise must have made Otis think that there was something living in this space.