What are the Largest Rodents?


Common question submitted: “What are the largest rodents?”

The largest rat - Capybara.

The largest rat – Capybara. They are a member of the rat family and can grow up to 4 feet long (1.2 meters) and weigh as much as 100 lbs. (45.4 kilograms).

There are about 2,277 species of rodents. Among the largest common rodents are beavers and chipmunks. However, most people associate the term “rodent” with rats or mice. The largest rats are giant rats — 82 cm (32 inches) long, found living in New Guinea. The Capybara is a member of the rat family and can grow to 4′ long and anywhere between 75 and 100 pounds.

Fun Fact: An extinct relative of the rat, Josephoartigasia monesi, was as big as a bull, but lived over 2 million years ago and may have weighed in at close to a ton.

Sewer rats found in the United States can get quite large like the rats lurking in New York’s subways, but these are hardly record-breaking in size compared to rats found in other parts of the world. Most of the varieties reported in the news as being unusually large are actually invasive species to the United States introduced by breeders or people that had them as pets at one time or another. For example, the Gambian pouched rat (Cricetomys gambianus) is native to parts of Africa, but in recent years this invasive species has been found living in the United States. The Gambian pouched rat has been found in areas including New York and has invaded The Florida Keys. They can get rather large weighing in at over 3 lbs. and with a body length of up to 18 inches not including their tail.