Hamster balls are hollow spheres made of clear plastic into which hamsters, gerbils, degus and other small rodent pets are placed, allowing them to run around outside their cages without the risk of running away or getting lost under furniture.[1] They are designed to provide hamsters with exercise.[2] Balls produce an audible rumble across most surfaces, making them easier to locate even when out of sight.
Hamster balls have been manufactured and sold since at least the 1970s.[3] Most are made of durable transparent plastic with air holes and a small door or lid to allow the owner to insert or remove the hamster from the ball.[4]
Although hamster balls are designed to protect hamsters, there are hazards such as stairs and other high places from which hamsters can fall, resulting in injury or even death. To protect hamsters, owners may place hamster balls on the lower level of their house, away from any stairs.[5] Some owners also create a simple barrier near the stairs, so that they will not roll down the stairs.
Although hamster balls have air holes, hamsters should be allowed to take breaks and leave the ball regularly due to a lack of water that could induce heatstroke or exhaustion. It is important to keep watch over the hamster ball at all times while the pet is inside.[1] The ball can pick up too much speed, causing the hamster to somersault inside and potentially be injured.
Hamster balls are recommended by the manufacturers for use with hamsters, gerbils, mice, degus and small rats only; they should not be used for chinchillas or guinea pigs, as their size and body structures are different from small rodents, posing a serious hazard to them if placed inside.[6]