Welcome to the big curvy colourful world of Rotastak cages. Rotastak cages make fantastic homes for your hamster, mouse or gerbil. Made with expansion in mind, with Rotastak cages you can add rooms and tunnels to your cage whenever you want to. Armitages Rotastak cages have been designed to be as much fun for your small pet as possible, with tubes to crawl through, and wheels to run and exercise in.