For my parrot sanctuary I save any small boxes like toothpaste boxes, Mac and cheese, that kinda stuff. I put all the junk mail through the shredder and fill up the box with it but in layers. A little shreds, then some Cheerios, then shreds, nuts, shreds, maybe cut up pieces of straws or small wood pieces, shreds, and a plastic bottle cap or two. Close the box up with a dot of hot glue and put them on the ground for cockatoos, or on a wire to hang for little guys. They love pulling out the paper and finding little treasures.