I'm in the middle of "The Amazing Maurice and his Educated Rodents," by Terry Pratchett. And since it's by Terry Pratchett, it's hilarious, of course. Here's a brief excerpt that I think illustrates Pratchett's wonderful sense of humor:
Darktan turned to Number Two platoon. They were some of the older rats, scarred and bitten and ragged, some of them with stubs of tails or no tails at all, some of them missing a paw or an ear or an eye. In fact, although there were about twenty of them, they had among them only enough bits to make up about seventeen complete rats.