One day, Milo the Cat was checking to see that everything was okay around the house. His human sisters were at that place where they take the bags he likes to sleep in. (For the humans, this place is called school, and the bags are backpacks.) Milo's parents were also off on some adventure. Milo finished his walk-through, and decided to settle down for a nap when -- what's this? Something small and grey wiggled behind him. He chased it, and chased it, but he couldn't seem to catch it. This thing was really there, and it was definitely not a mouse or a toy. What was it?