Okay, so if guinea pig bedding is safe for compost, what about the bedding my granddaughters use for their pet mice?

I've had both the front & rear tine tiller. My first garden was in beautiful deep sandy loam (How perfect was that?!)and the front tine tiller did a wonderful job. After moving, I used the faithful front tine tiller to make my new garden, but it didn't do so well in the rocky, caliche soil. It bounced and bucked and shook my bones. So after some research, I bought a rear tine tiller that was much easier to use in the rocky ground - no bucking and bouncing and it churned right thru that hard caliche. So I guess I would say that size isn't the only consideration in choosing your tiller but also the type of soil you have to work with.