This project uses a Finder and a Drawer. The Finder moves up and down and reports a variable "1" when touching the cat, "0" when not. So whenever the variable is "1" the Drawer stamps, creating a perfect shadow. Whenever the Finder is not touching the Cat for 20 seconds after the Finder has already touched the Cat, it stops all. Takes about a minute for the Finder to find the Cat. Please Love-it for more.