Daisy, my female Syrian (about 5 months old) keeps putting toys, chews, bits of dry food, etc. in her wheel (11-inch Silent Runner). She does use her wheel to run in but also sometimes just sits in it. Each day I've removed at least the larger items, since I can't imagine how she can run in the wheel with so many things in it -- some of them are 3-inch wood chews! -- but every day she puts things back in.
I do bring her out to a playpen each night that has another wheel in it, and she uses it to run, and maybe occasionally puts some items in it, but not all the time.
I wonder if she's claiming the wheel in her cage as her territorial space. Or maybe she likes running in it with all the items bouncing around? I don't want her to hurt herself, and I want her to have access to a wheel she can comfortably run in.
I've thought about putting in a second wheel, but there really isn't room for another 11-inch without blocking one of the access doors, and I wouldn't want to do it if it's not necessary. (FYI, she's in a 32" x 18" barred Pet Prevue cage, 576 sq inches). Besides, she might do the same "home redecorating" in the second cage anyway...?
The last couple days I've removed the larger items each morning but left the smaller bits in there. But I'm not sure if it's helpful to the situation, since she puts the larger things back in each night anyway.
Please help, if you have ideas or suggestions. Thanks.