The Capybara is the biggest rodent on earth. These impressive semi-aquatic mammals are found throughout much of northern and central South America. They are closely related to guinea pigs and rock cavies.
Capybaras are strong swimmers and even their toes are partially webbed for paddling around in the water. In fact they can remain completely submerged for up to 5 minutes! But eeeew! They eat their own faeces as a source of bacterial gut flora, to help digest the cellulose in the grass that forms their normal diet, and to extract the maximum protein and vitamins from the food. So there is a good reason they do it!