Voles and cotton rats usually live in different geographic regions, but both groups of small rodents eat grass and make runways. Yellow-nosed Cotton Rats are especially vole-like because they are small and live in grassy patches of habitat in mountains. Learn more about the Sigmodon ochrognathus, more commonly known as a Yellow-nosed Cotton Rat, in this easy-to-read species overview by the Smithsonian's National Museum of Natural History.