Review on 🐹 Lee's Kritter Krawler Jumbo Exercise Ball: 10-Inch, Clear - Ultimate Pet Workout Experience! by Cindy Martinez

Must put 2 because the doors are difficult to open and the running balls are really not harmless to any animal and should only be used while clearing a temporary case when you have nowhere to go. Although I suggest a clean, dry bath with some toys instead! At the very least, hamsters have poor eyesight and rely on their other senses. So if you put them in a plastic ball, they become meaningless. They may think they are having fun running around, but in reality they are panicking and trying to find a way out. Haven't used mine since researching it and wish I had before I bought it. It's a shame that pet supply companies care more about making products for sale than about the safety and welfare of the animals they are "made" for, because they shouldn't be made.