Specially designed to make exercise easy for dwarf hamsters and mice, these perfectly sized run-about balls allow tiny pets to maneuver with greater ease. Our moon glow mini run-about balls glow in the dark while providing pets and pet owners with interactive fun during playtime. Mini run-about balls also make a great temporary area to keep your little critter while you are cleaning their cage. For added safety, use your mini run-about ball on super pet"s hamtrac raceway and provide your pet with a controlled exercise environment.