How to Make a Tunnel Playground for Your Gerbils. Making a tunnel playground for your gerbil is a fun way to bond with your pet. It's also a great way for your gerbil to get some much-needed exercise! You can make a tunnel or even a maze. Hamster Diy Cage, Gerbil Cages, Hamster Life, Hamster Habitat, Hamster Stuff, Dwarf Hamster Toys, Pet Mice, Pet Rats, Diy Gerbil Toys