. Here's another one for rats from Robin. "My husband and I made this 4-floor cage for our pet rat (who can be seen sleeping on the balcony in the pictures). It cost around $30 for the Gorm shelf unit (5 of the 20x20 size shelves and 4 uprights) and another $40 at the hardware store for the wire mesh, hinges, wood trim that makes the door, and hook latches.
