The animal known as the world's largest rodent is the capybara (Hydrochoerus hydrochaeris). Native to South America, capybaras can weigh up to 140 pounds (64 kg) and measure about 4 feet (1.2 meters) in length. They are semi-aquatic mammals typically found in swampy or marshy areas. Capybaras are highly social animals, living in groups that can number up to 20 individuals. Their diet mainly consists of grasses and aquatic plants, and they are known for their friendly demeanor, often coexisting peacefully with various other animal species. They play an essential role in their ecosystem by influencing plant growth and providing a food source for predators.