In this episode, the focus is on Carla, a young capybara living with her family in the swamps and grasslands of Venezuela's Orinoco river. The capybara is the world's largest rodent: it is the size of a sheep, barks like a dog and is happy in the water and on land. Carla spends her days grazing and swimming. Baby capybaras start swimming at just a few weeks old. They have nostrils which seal tight, and their flipper-like webbed feet help propel them through water. Their eyes, ears and nostrils are all located on the top of their head so that they can see, hear and breathe as they swim. They also manage to remain almost invisible to predators. However, capybaras don't have much sense. A full grown capybara may weigh as much as human, but its brain is the size of a lemon!