A pet litter box, comprising: a housing having left, right, front and back side walls defining a well, the housing including at least one ridge disposed on a side wall and at least one depression disposed on at least one side wall a grid having plurality of holes between grid lines and configured to slide into the depression of the side wall of the housing and a locking frame having an open interior, configured to slide and lock into the well of the housing, below the ridge and over the grid.
