Since the capybara keeper at Izu Shaboten Park noticed his charges relaxing in a puddle of hot water in the winter of 1982, roughly 20 zoos across Japan have taken up the practice of preparing a capybara rotenburo, or outdoor hot bath, to get the big rodents through the colder months.

Capybara love water, and have the webbed feet to prove it. The largest rodents in the world, these South American animals can grow up to 134 centimeters (4 ft 5 in) long and 66 kilograms (146 lbs) in weight. They also squeal like guinea pigs and purr when you pet them.

The citrus fruits you’ll see in some of the images are added to make the water more aromatic, in keeping with the Japanese tradition of bathing with yuzu (a sour citrus) on the winter solstice, which is supposed to promote circulation and reduce sensitivity to cold. However, the capybara aren’t all that particular, and will also sometimes use grapefruit and pomelos.

Izu Shaboten Park is located in Ito City on the eastern side of Shizuoka’s Izu Peninsula. In the winter of 2015, the park held a Facebook competition with Saitama Children’s Zoo, Nagasaki Bio Park and Nasu Animal Kingdom in Tochigi Prefecture, with each posting photos of their bathing capybara. When the like-off wrapped, Saitama came first with 4,260 likes, Nasu came second with 3,700, then Ito with 3,626, and finally Nagasaki with 2,428. While Saitama has an advantage with five times the population of Nagasaki, videos like the one above probably didn’t hurt, either.