I discovered a new toy that Acorn LOVES and it also helps to keep him from digging at the carpet, and it is just one of those puffy things that you use in the shower.
I had just gotten a few new ones and when I got home from the store, Acorn pulled one out of the bag and started running around the house like crazy, every time he got back to the ball thing, he would stop, dig at the ball for a minute, and then run around again.
I wouldn't suggest giving one to your buns if you know they like to eat their toys because I am sure the little plastic pieces would not be good for them to ingest. My boys are both good about that though and they never actually eat their toys (they don't even eat the paper I give them to shred up, just leave it in piles for mom to clean up).
Anyways, I made this discovery last week and I have left Acorns ball out for him to play with. I noticed that he used to dig at the carpet quite a bit, but now, instead of doing that, he will dig at the ball. . . . . come to think of it, I am going to have to try to get a picture or some video of that. . . . . It is a big shower ball so it looks pretty funny to see him going at it!