Okay! I like this subject! My sage is litter trained. I use Feline Pine . She loves it , I love it , and she has never had mites from it! I just put the litter in a low cut shoe box , she goes in , does her business , and that is that! I tried all kinds of litter , and the only one she will use is Feline Pine. (Same goes for my cat! those two are like peas in a pod!) As for wheel , i think it is a good idea to put wheel in the litter box , as they do tend to go a lot while running.