Drill or cut a 'feeding' hole near the bottom, small enough that your bird's head can't get stuck in it. Next poke or drill a hanging hole in the lid. Lastly fill it with hay or paper shred plus seeds and treats throughout!
Minimalist IKEA Cabinet Hack, and lots of other ideas on hiding a litter box. Not just for the litter box but for a dog's or cat's pet bed, when company is over or just during the day, just shut the door and it won't have to be seen until bedtime.