and Cathy Bickel
Gerbils love wheels, but they can be dangerous if you don't know what to look for.
To lessen the chance of injury to feet and tails, the wheel should be solid plastic, such as a Silent Spinner, or made of metal mesh. When buying a metal mesh wheel, check for sharp points both where the mesh is welded to the circular frame, and where the mesh is joined to the other end of itself.
Gerbils need a wheel in the 8-inch size.
When there are gerbils of mixed ages in the cage, such as parent gerbils with their young pups, the wheel should probably be removed. Mom or dad will not always stop running when a pup joins them in the wheel, and the pup could be injured when he gets thrown out as the wheel spins.