Imagine this. You're sitting quietly at the table eating breakfast in the morning, all alone. The house is dim and silent. Then all of a sudden you hear a thump. You listen for a moment, then forget about it. But then, another thump, sightly louder. And it continues every few seconds, and now you can tell it's getting closer. Thump, thump, thump. An finally, slowly emerging from around the corner is the face of your two-year-old, who just came down the stairs. I was pretty sure it was her, but it was still surprisingly creepy.