From publisher blurb:
Rodents are the most numerous of all mammals. They are very adaptable and are found in practically every environment on the Misty Isles. Some species, especially mice, voles, and rats, survive at the bottom of the food chain by their sheer fecundity.
Rodents is a bestiary article. It describes the habitat and physical attributes of Hârnic rats, beavers, and squirrels, with full HârnMaster stats. Also included are rules for rodent infestations.