The word “rodent” comes from Latin and means “to gnaw” — which is exactly what these critters do, with incisors that never stop growing. When you hear the word “rodent,” you probably picture a rat or a mouse. However, did you know that porcupines, beavers, and capybaras are rodents, too? Plus, some of them can grow really big. Let’s take a look at the largest rodents in the world.
12. Nutria (Myocastor coypus) – 20 Pounds
Nutrias reproduce quickly, which is one of the reasons they cause problems in new habitats.
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Also known as coypu or swamp rats, nutrias are large rodents native to South America. However, they have also been introduced to the United States, where they overpopulate and disrupt the natural ecosystem. Nutrias grow to about 17-25 inches long with a 12- to 18-inch long tail. They typically weigh 15-20 pounds.
Nutrias look something like a small beaver or a giant rat. They are ravenous animals and often eat every last part of plants. They also eat insects and snails. In some areas, they have been known to eat crops like corn, sugar cane, and rice. Nutrias are aquatic animals and live together in burrows connected by tunnels near freshwater.
11. Paca (Cuniculus paca) – 26 Pounds
In some areas, people hunt pacas for their meat.
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Also known as the spotted paca or lowland paca, this rabbit-sized rodent lives in Central and South America. Pacas have dark brown fur with white spots on their sides that often connect and look like stripes. They measure up to 32 inches long and can weigh up to 26 pounds.
Pacas prefer to live in swamps, wetlands, rainforest habitats, and areas close to water sources. They are primarily frugivores, which means that they mostly eat fruit. However, they can eat a wide variety of different plants as well. Pacas are nocturnal animals that spend their days sleeping in burrows. They live alone or in pairs, but each member often has their own separate den.
10. North American Porcupine (Erethizon dorsatum) – 30 Pounds
North American porcupines have nearly 30,000 quills.
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The second largest rodent in North America is the North American porcupine, weighing in at 30 pounds and growing from 25-31 inches long. North American porcupines are native to the forests of Canada, the United States, and northern Mexico.
Porcupines live in a wide range of habitats, from mixed forests and desert shrub environments to grasslands and even tundra. Although North American porcupines are excellent climbers and occasionally build their nests in trees, they spend most of their time on the ground.
9. Pacarana (Dinomys branickii) – 33 Pounds
Pacaranas are mostly found in parts of Venezuela, Colombia, and Bolivia.
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Scientists still don’t know a lot about pacaranas, as they are very secretive and rare. These large rodents grow up to 31 inches long and weigh up to 33 pounds. They live in Central and South America, often in the hills and valleys of the Andes Mountains.
Pacaranas have dark brown bodies with two white stripes running down their backs and white spots along each side. They have elongated heads, long whiskers, and small rounded ears. When they eat, they often sit back on their hind legs, holding their food carefully between their two front paws. Pacaranas have a complex communication system, with a wide variety of sounds and body movements.
8. Patagonian Mara (Dolichotis patagonum) – 35 Pounds
Patagonian maras mainly eat grasses, but on occasion, they may snack on fruits, seeds, and flowers.
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About as big as a medium-sized dog, the Patagonian mara grows up to 30 inches long and generally weighs 17-35 pounds. This unusual animal has a stocky face and body like a capybara. However, it also has long, skinny legs more like those of an ungulate, or hoofed animal. In addition, it has tall ears and sits with its weight on its back legs like a rabbit. It has dense, gray-brown fur with a white patch on the chest and stomach and orange coloring on the cheeks and chest.
Patagonian maras only live in central and southern Argentina in brushlands and arid grasslands with lots of open space. In addition to their unusual appearance, Patagonian maras can walk, hop like rabbits, gallop, or even bounce on all fours.
7. Indian Crested Porcupine (Hystrix indica) – 40 Pounds
Porcupines also have thick claws.
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Native to the Middle East and southeastern and central Asia, the Indian crested porcupine is a large rodent that weighs 24-40 pounds. Its body is covered with several layers of modified hair quills. The underlayers contain short, thick quills, which cause most of the damage. The top, outer layers have longer, thinner quills. Each quill has alternating bands of white on a brown and black background. Their tails have short, white spines. Some of these quills are also hollow and make loud rattling sounds. These quills can grow to nearly 16 inches in length.
Indian crested porcupines are nocturnal animals and can travel nearly 9 miles at night in search of food. They spend their days sheltering in caves or burrows found in rocky areas, forests, tropical regions, plantations, sandhill deserts, mountain steppes, and even up in the Himalayan Mountains!
6. Lesser Capybara (Hydrochoerus isthmius) – 62 Pounds
Lesser capybaras essentially look like smaller versions of greater capybaras.
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The lesser capybara can be found in western Venezuela, eastern Panama, and northwestern Colombia. Although they are closely related to the larger, common capybara, lesser capybaras are measurably smaller. Lesser capybaras grow up to 36 inches in length and weigh up to 62 pounds.
Lesser capybaras are semi-aquatic mammals and always live near standing water. Although they are social, they are not as gregarious as their larger cousins and often live in much smaller groups. They also have a smaller range, whereas the greater capybara is more widespread throughout South America.
5. African Crested Porcupine (Hystrix cristata) – 66 Pounds
“Porcupine” is Latin for “quill pig.”
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African crested porcupines are one of the largest porcupine species, growing from 24-36 inches long and weighing 22-66 pounds. Their range includes Italy, Sicily, North Africa, and sub-Saharan Africa as far south as the northern Congo. Like other porcupines, its body is covered in sharp quills that range from 1-13 inches long.
The African crested porcupine gets its name from its defensive posturing. When it senses a threat, the porcupine raises the long quills on its head and neck, forming a crest that makes it look bigger and more intimidating. It may also stamp its feet, rattle the hollow quills on its tail, and click its teeth. If the threat remains, the porcupine runs backward and rams the target with its thick tail quills.
4. Cape Porcupine (Hystrix africaeaustralis) – 66 Pounds
Cape porcupines are monogamous and live in small family groups.
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Native to Central and South Africa, the Cape porcupine is the largest rodent in Africa and the largest porcupine on Earth. Cape porcupines grow 18-36 inches long and weigh 39-66 pounds. They are very adaptable animals and can live in many habitats. However, they are more common in open areas. Cape porcupines live in small family groups and often shelter during the day in caves, rocky crevices, or underground burrows. At night they hunt for food.
When they walk, Cape porcupines can look a bit awkward. However, they can easily outpace humans and several other animals when they run. Their bodies are covered with long quills and spines made of hardened, modified hairs. Their quills alternate between bold black and white colors, serving as a warning to potential predators. They also have specially modified hollow quills that they can rattle to make noise.The quills around their back and tail are thicker, shorter, and closer together, serving as another built-in weapon.
3. Eurasian Beaver (Castor fiber) – 66 Pounds
Eurasian beavers are smaller than North American beavers.
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Growing up to 4.3 feet long and weighing up to 66 pounds, Eurasian beavers are the third largest rodents in the world and the largest rodent in Europe. They have a similar appearance to North American beavers. However, their skulls are slightly longer and more narrow, their tails are thinner, and their fur is a bit lighter in color. Eurasian beavers once lived throughout Europe and Great Britain, but sadly, they were nearly hunted to extinction for their meat, fur, and scent gland secretions (castoreum).
Fortunately, successful conservation efforts and reintroductions have helped populations of Eurasian beavers to recover. These large rodents are extremely important to the ecosystems where they live. As ecosystem engineers, Eurasian beavers build dams that help create wetland areas, providing crucial habitats for other animals like amphibians, fish, and birds.
2. North American Beaver (Castor canadensis) – 85 Pounds
Beavers help to reduce erosion and create habitats and resources for other animals.
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The second largest rodent in the world and the largest rodent in North America is the North American beaver. These enormous rodents grow 3-4.5 feet long. They weigh 35-85 pounds, with some large individuals weighing even more.
They have unique, paddle-shaped tails that are flat and scaly, as well as webbed feet. Their massive front teeth are orange due to the high iron content in their enamel. Beavers are incredible ecosystem engineers, cutting down and shaping trees as they build dams, which can significantly transform their habitat. They are also a keystone species.
1. Capybara (Hydrochoerus hydrochaeris) – 174 Pounds
Capybaras have eyes and ears close to the tops of their heads, allowing them to stay mostly submerged in the water.
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The largest rodent in the world is the capybara. These adorably large rodents can stand up to 1.6 feet, measure 3.2-4.2 feet long, and weigh 60-174 pounds, depending on sex. Despite their large size, they are calm and friendly animals that are well-known for their social, outgoing natures.
Capybaras live in Central and South America. They are semi-aquatic mammals with shaggy, light brown hair and slightly webbed feet. They are excellent swimmers and always live near marshes, riverbanks, ponds, and other water sources. Capybaras can also hold their breath and stay underwater for up to five minutes at a time, which is a common strategy to escape predators.
Bonus: The Extinct Giant Pacarana (Josephoartigasia monesi) – 772 Pounds
So far, paleontologists have only found a skull from the giant pacarana.
©Andrés Rinderknecht & Ernesto Blanco; Illustration: Gustavo Lecuona / CC BY-SA 2.5 - Original / License
If you think the capybara is big, wait until you see the giant pacarana. This massive rodent was the size of a bison. Around three million years ago, giant pacaranas roamed across the southern regions of South America. Scientists originally estimated that giant pacaranas weighed over a ton, based on a 1.7-foot-long skull found in Uruguay. However, recent studies suggest it was closer to 772 pounds, which is still a monumental size for a rodent.
Scientists estimate that the giant pacarana had a bite force of over 300 pounds at its incisors and 936 pounds at its molars. However, like many rodents today, giant pacaranas appear to have enjoyed a diet of forest and water plants.
