I personally won't even put my hamster in those hamster balls. It may seem like your hedgehog (or hamster) is having a blast but when a hedgehog is in one of those balls, you basically take away it senses. It sense of smell is cut off, it's hearing is cut off too, and it's certainly not going to give the hedgie a better view of the world. And honestly, constantly crashing into walls and objects does not sound fun for a hedgehog. I'm sure if your hedgehog has a chance to escape those balls, it will. But of course, when they try to climb up the sides, they just end up rolling. And really, it just takes the fun away from you. How can you interact with you hedgie when its trapped in a ball? And obviously the ventilation isn't fantastic either.