Found across almost the entire globe, rodents have learned to thrive in deserts, grasslands, and especially around human settlements, where some species (like mice and rats) have become common pests. Humans keep some rodents as pets, but even wild ones (such as squirrels and chipmunks) have learned to live in harmony with us in the city and suburbs. Although usually thought of as small -- with the more common species being small enough to hold in your hands -- there are others, like the Capybara, which can grow to the size of small dog.