A pet litter device (100) includes: a base (20) configured to be placed on a support surface, the base defining a recessed portion (21) that comprises a recess surface (212) defining an opening (211), and a drum (10) rotatably connected to the base and partly received in the recessed portion. The drum has an outer lateral surface (101). The recess surface and a portion of the outer lateral surface that faces the recess surface define a gap ( d ) and form a passage (30) in communication with the opening. The recess surface is to guide litter particles entering the passage to pass through the opening to fall on the support surface.