Hedgehogs are energetic pets that exercise almost constantly, spending long stretches of time on their exercise wheels. The danger is that their small feet can get caught between the bars of a standard-sized wheel. Some pet stores sell wheels designed specifically for hedgehogs, but if you can't find one or have already invested in a standard model, simply use duct tape to cover the bars and prevent their feet from slipping through. While this trick works for hedgehogs, gerbils and hamsters shouldn't be afforded the same treatment. Their feet are fine one standard wheels and they will chew away the tape.