Photograph: Molly HigginsNot RecommendedPetSnowy Snow+ Self-Cleaning Litter Box for $680: This box looks like something from Kubrick’s visions of space travel, or if Eames started making plastic litter boxes. My cats had a really hard time using it—they just couldn’t understand that it was a litter box. The Pet Zone Smart Scoop for $166: This is probably the least “smart” automatic litter box we've tested—it's a typical rectangular plastic box with an automatic arm that acts as a rake and scoops the clumped (soiled) litter into a small bin on the other side. You’re only allowed to fill the litter box with about an inch and a half of litter, which my cats didn’t like (they prefer a few inches to really bury it). My cats tend to pee on the side of the litter box, which, because of the rake’s placement, means it misses an inch on either side—I still had to scrape the caked-on litter from the edges.