DIY Gerbil cage
Guinea Pig Cage from an old book shelf
Homemade hamster cages using Habitat Modules and Additions, would be difficult to keep clean though.
Projects to Try
How to: DIY Three Story Gerbil Cage Also Good For Hamsters made from plastic storage containers.
DIY hamster cage - Google Search .... GENIUSES!!!!!
Oooh, we might have to try this for hanging our water bottles in the gerbil cage.
How to Make an Aquarium Into a Gerbil Cage: 12 Steps
My DIY Hamster Cages
Cool Hamster Cage Biddie Buddies Palace
Image titled Make an Aquarium Into a Gerbil Cage Step 3