Abstract: A pet litter tray, box and system. The litter box comprises multiple trays. The trays are nestable within one another. Each tray comprises a base defining one or more openings. The opening allows litter to pass therethrough. When stacked in a first orientation, the openings of each upper tray are blocked by portions of the base of the adjacent lower tray thus retaining the litter. The top-most tray is lifted to sift the unused litter into the two nested lower trays. The top-most tray is added to the bottom of the two nested trays in a selected orientation. The trays may comprise flanges extending from the openings to contact the base of the lower tray when stacked to retain litter. The trays may comprise protrusions extending from the rim to contact an adjacent lower tray to indicate improper orientation of the trays.

Abstract: A pet litter tray, box and system. The litter box comprises multiple trays. The trays are nestable within one another. Each tray comprises a base defining one or more openings. The opening allows litter to pass therethrough. When stacked in a first orientation, the openings of each upper tray are blocked by portions of the base of the adjacent lower tray thus retaining the litter. The top-most tray is lifted to sift the unused litter into the two nested lower trays. The top-most tray is added to the bottom of the two nested trays in a selected orientation. The trays may comprise flanges extending from the openings to contact the base of the lower tray when stacked to retain litter. The trays may comprise protrusions extending from the rim to contact an adjacent lower tray to indicate improper orientation of the trays.

Abstract: A device for sifting a siftable material comprises at least three nestable trays. The trays are stacked to form a vertically stacked array. Each tray has a base having a plurality of ribs defining a plurality of openings sized to permit the material to pass through, while preventing passage of large objects. The openings of each tray are arranged in a pre-set pattern so that pairs of trays may be nested together with the openings of one tray blocked by the ribs of the other. The trays may be identical with the openings arranged asymmetrically in the base of each tray, so that the necessary interference or blocking is achieved by rotating each tray relative to the adjacent tray. Alternatively, the openings can be symmetrically located with two different trays being provided, having complementary patterns of openings. The stacked array of trays can be configured as a cat litter container, or used for sifting a variety of the material.