My Louise used to climb to the very top of her wheel and sleep belly up
on her wheel.
Yes, her old wheel was far too small. So I upgraded her recently (ordered online and it took a while to arrive).
Guess what? She decided to sleep in the exact same spot as before (so now she's sleeping behind the wheel).
Photos of her on her old wheel and behind her new wheel attached. I think she just likes the breeze and the cold metal bars.