"Scratch"

"Scritch, scratch"

I wake up to this sound reverberating around the room.  What is that?  Finally opening my eyes, I look straight up at the ceiling at first, then I focus on the wall.

Slowly scanning as my eyes move down the wall, they catch something moving in the corner. It's quite dark in the room with barely any moonlight, so I must squint to see. Watching silently, I notice when it moves again. As my eyes focus on it, it grows clearer, and I see exactly ...