Automatic litter boxes vary depending on the brand and litter box type. Generally, they have sensors, either by motion or weight, to tell when a cat has entered or exited the litter box. Usually customizable and controlled via app on your phone, or on a more rudimentary timer system, the cleaning cycle will begin a short time after the cat has used the box. With the dome-shaped litter boxes, the cleaning will happen via a cycle where the litter spins and rotates around the spherical interior; the bigger soiled clumps will be deposited into the waste basket while the clean litter passes through the grates and gets recycled back into the litter box.
The Neakasa M1, for example, rotates backward and then forward (rather than a spin cycle) to sift the clumps from the clean litter, depositing the larger clumps into the waste basket. The Pet Zone Smart Scoop is the most rudimentary on our list, simply using a rake attachment to scoop the bigger clumps into a waste receptacle in the back.