The largest rat in the world is a rodent that you probably wouldn’t want to meet face-to-face.
Capybaras are large, semi-aquatic rodents native to South America. They have been reported to grow as long as 4 feet (1.2 meters) and weigh as much as 150 pounds (68 kilograms). That’s about the size of an average beagle! And they have big appetites, so if one were to wander into your backyard there would certainly be trouble. Capybaras live in groups called “herds” that can consist of more than a hundred members spread across different families. The young males, or “bulls,” will leave their herds when they reach adulthood and become loners until they find a female with which to mate.
Capybaras eat aquatic vegetation, such as water hyacinth, and grasses that grow near the water’s edge. They also can stay underwater for up to five minutes to hide from predators or gather food on the bottom of rivers and lakes where nothing else will grow.
So far as is known, they have no natural predators except humans.
There are many rodents in the world today, so why is it believed that capybaras are the largest? Because as a group of animals called “caviomorphs,” this family includes some truly gigantic rodents. The biggest living caviomorph is probably the capybara’s slightly smaller cousin, the guinea pig.