The Charismatic Capybara Is Chiller Than Your Dog

For some reason, not everybody loves rodents — maybe because a few species are pretty persistent in their efforts to share our homes with us. And rats have long been credited with spreading the bubonic plague, which killed millions of people in medieval Europe and Asia.

But the order Rodentia is vast — in fact, a whopping 40 percent of all mammal species are rodents. Which means the Norway rats you glimpse in the shadows of the subway tunnel and the house mice setting up a nursery in your attic are both rodents, but so are beavers, guinea pigs, porcupines, chipmunks and nutria. There's a lot to love there, but maybe none so charismatic as the world's largest rodent: the capybara.

Charisma is, of course, very subjective. Picture this, though: a giant pig-like, semi-aquatic rodent about the size of a large dog whose eyes, ears and nostrils sit basically at the top of its head. They also have these weird, tiny webbed feet that look kind of like hooves. They are vegetarian and eat between 6 and 8 pounds (between 2.7 and 3.6 kilograms) of grass each day, in addition to their first poop of the morning. That poop contains lots of protein from the microbes that have been feasting on the contents of their intestines all night; eating it allows them to get nutrients out of the food their system didn't absorb the day before. Fascinating.

Capybaras (Hydrochoerus hydrochaeris) — and, just to get this out of the way, the plural of the word capybara is indeed capybaras, not capybara — are native to Central and South America, where they're doing extremely well. The International Union for Conservation of Nature (IUCN) considers them a Species of Least Concern, even though they serve as a prey item for everything from anacondas to jaguars. Capybaras need to stick pretty close to water — a wetland, estuary, river, etc. — not only because they need to keep their skin moist, but also because they require access to the grasses that grow near waterways. About 80 percent of their diet comes from five different riparian grass species.

Capybaras Are Very Social Beings

Another thing capybaras need is each other.

"Capybaras are among the most social of rodent species," says Elizabeth Congdon, a capybara researcher and professor in the Department of Natural Sciences at Bethune-Cookman University. "Groups consist of a dominant male and several subordinate females that tend to be related to one another, and their offspring. Females cooperate with one another to the point of nursing another's infants and collectively defending the young of the group against predators and potentially infanticidal males. I have personally seen an adult female back down a large spectacled caiman that was approaching her newborn."

Groups of capybaras can range from around 10 up to 100 during the dry season, and for the most part their daily activity involves a whole lot of chilling. Some have called capybaras "nature's ottomans" because all sorts of animals like to sit on a capybara's broad back: monkeys, birds, other capybaras, you name it. Females like to play with their young, teaching daughters to be allies to one another and sons to be competitive. But since capybaras have so many predators, and since a single male works hard to keep as many females to himself as possible, males are constantly on the lookout for funny business.

"The male will aggressively defend his rank," says Congdon. "These interactions between males don't always reach the level of a full fight because grunting and chasing will usually do the trick. Females not only stay in the group, but also help defend the territory against outsiders and predators by alarm calling when sighting one."

And while it's true that capybaras are charming and some people have begun keeping them as pets (which is legal in some U.S. states like Texas and Pennsylvania, although in most places you'd need to get a special license), keeping a capybara in your home isn't for everyone, or even the vast majority of people. Capybaras require a lot of water, space and friends — a solitary capybara or even a pair of them would probably be very unhappy. In Florida, several have escaped — probably from a wildlife research facility — and are hanging out in North Florida, possibly snuggling each other with birds sitting on their backs. It remains to be seen whether capybaras will become Florida's next invasive species.

Learn more about capybaras in "Capybara: Incredible Pictures and Fun Facts about Capybara" by Lueretha Atkins. HowStuffWorks picks related titles based on books we think you'll like. Should you choose to buy one, we'll receive a portion of the sale.