They look like giant guinea pigs, they eat their own poop, and the Vatican once declared that they were fish.

Capybaras – the world’s largest living rodents, external – are unusual animals to say the least, and in recent years – helped by some high-profile capers – the capybara craze has gripped people across the world.

Now, a filmmaker has made a documentary all about them.

“I loved capybaras before they were viral, I’ve loved them for many, many years, but I’m so glad they’re having a moment,” says Sharon Walia, who explores the popularity of the huge herbivores in The Route to Cappyness.

“There’s merch, there’s kids with the school bags, there was the Oscar-winning film Flow which featured a capybara, and they’re popping up everywhere on memes,” Walia says.

“I don’t even think this is a moment, I think this will last because it’s been going on for years now and I just think people really, really love them.”