Drill or cut a big 'feeding' hole in the bottom and a hanging hole in the lid then fill it with hay or paper shred plus seeds and treats throughout!
Piggy Condos! SO STINKIN' CUTE! (this was a quick DIY project someone posted in a thread)
Must make this with my new sewing machine
What Guinea Pigs Eat - The Happy Cavy Diet
hammock holder with 1 hammock "red with white dots" for guinea pigs -funny but cute idea