Come home to a vacuumed house but no sign of Roomba? (let's be honest, it's vacuumed but not necessarily clean - anything that Roomba can eat gets picked up and put down on a higher surface)
Send for 'BA! Tracker.
Looked for mine during nap time and could not find it. Mac got up from nap and went to the docking station for the afternoon run of the 'BA! Because everyone knows that the 'BA! runs twice a day without fail. Complained loudly to me and then started to track it down. Dagnabit, the boy found it in five minutes! Of course we had to do the ritual of putting 'BA! to bed a little early today.