There's a hilarious story online somewhere about a family who programmed their robot vacuum to run starting at one a.m. They forgot about the fact that they had a new puppy in the house. As you might expect, the puppy pooped overnight, the robot vac ran through it and left a poop trail across several rooms. I had been interested in a robot vac until that point. But I have kitties who yak up hairballs on a regular basis, and I have no desire to clean them up here...and here... and here.

Here's the whole story on the "pooptastrophe":

[usatoday.com]

@citronella I don't set Roscoe to run after I go to bed. It make too much noise. One time it delayed cleaning for charging,and it stated up after all the lights were out. I saw lights from the living area, and I got my bat out of my closet. I'm so glad I did not call 911 on my Robovac. It only runs while I'm up, and I've never had a cat accident that I didn't catch before Roscoe ran. One of the cats like to box with Roscoe, which I think is why his cleaning was delayed.