A giant cousin of the guinea pig, the capybara is the largest rodent in the world, with adults generally weighing between 80 and 140 pounds. Capybaras are semi-aquatic herbivores that live in the dense forests near lakes, streams and marshes in Central and South America. They are usually most active at dawn or dusk, but they become nocturnal in areas where they are threatened by humans or other predators. (Photo by Traer Scott/Chronicle Books)
