Squeaker?

Okay so has anyone ever had their Flying Saucer Wheel start squeaking? It's just of late, I've noticed that it has and, since Teddi is on it most of the night, it can become quite distracting and annoying. At least I hope that it's the wheel squeaking. Has anyone had any experience with their hedgehog squeaking while running on the wheel? I've checked him and he doesn't seem to be hurt anywhere so I don't think they're squeaks of pain. As well he is eating, drinking, pooping and walking normally. So maybe they are just happy squeaks? Or it is the wheel. I really really hope it's the wheel.

Anyway please let me know about any experience you have had with either scenario.
Thanks!