Abstract: A prefabricated fully assemblable bird cage comprising a flat sheet of stiff material, a rectangular panel, formed centrally in the sheet bounded on the outside perimeter thereof by four straight prefold marginal depressions, defining respectively a top margin, opposed side margins and a bottom margin, each fold line arranged orthogonal to the other, the fold lines joined at their respective intersecting terminal ends to form a central panel of the enclosure, the rectangular panel having formed therein a large central opening, the edges of which reside in the panel; first and second end panels extending outward from the central panel including a first portion of each end panel that is arranged to be folded orthogonal to the central panel; opposed side panels extending respectively outward from the panel margins for folding toward each other in parallel arrangement to form respectively side panels of the cage; a pair of wide, short tabs extending from the straight prefold marginal edge depression formed in the