I give mine little balls that are supposed to be kitty toys, with these you just have to make sure when they start chewing them up alot to give them a new one. They like to tote them around and toss them. They also have little smooth stones (too big for them to eat of course) that they like to push around in circles. Toilet paper rolls are good as someone else suggested. Dust baths are great, too. Mine also have the little tiny tennis balls for little dogs to play with, they tote them around and drop them from the top of the cage.
Because I was born in the South, I'm a Southerner. If I had been born in the North, the West or the Central Plains, I would be just a human being.