By BBC Wildlife Magazine

Published: Monday, 18 September 2023 at 15:44 PM


You’re never far from a rat, the saying goes, but with more than 70 species around the world the size of this most common of rodents depends on where you are – and how you measure it.

In Britain you’re most likely to encounter the relatively diminutive brown rat (Rattus norvegicus), 15-27cm long, nose to tail, and weighing 200-300g – but that’s small fry when it comes to the largest rats on the planet .

The world’s biggest rat in terms of length is African native the Gambian pouched rat (Cricetomys gambianus), with a body size of 43cm and a tail measuring a further 45cm – 88cm in total – weighing an average of 1.3kg.

They like to live in crevices and holes, hollow trees, or even a termite mound and feed on a diet of insects, snails, nuts, seeds and fruit.

Challenging them for the biggest rat title, on sheer body size, is the Sumatran bamboo rat (Rhizomys sumatrensis). Its tail is just 20cm long but its body, measuring 50cm, weighs in at a whopping 3.9kg. Definitely earning it the heaviest rat title.

Unlike the Gambian pouched rat it enjoys a vegetarian diet of bamboo roots and shoots, seeds, fallen fruit and leaves

The largest rodent in the world is the capybara

Main image: The Gambian pouched rat © Louisvarley, CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons