Domestic rats are a popular pet in the UK, known for their small size and inquisitive nature. Wild rats are less known. In the UK wild rats are often seen as pests, and with recent headlines suggesting ‘Rats as big as cats’ are ‘terrorising’ and ‘plaguing’ UK towns, it is no wonder people are a bit concerned.

So giant cat sized rats, are they real?

The short answer is yes, they are, but maybe not in the way you are thinking.

A quick google search will reveal several alarmist headlines stating cat sized rats are running a riot in the UK. The rats being referred to in these articles are mostly the Brown rat (Rattus norvegicus). Other less flattering nicknames for this furry beast include the common rat, street rat and sewer rat. 

So how big can Brown rats get? How long do they live and why are they making the news?

Brown rats are one of the larger species of rats found in the wild in the UK. They can weigh up to 500g but are usually around 200-300g. They can be anywhere between 15-27cm in length and have a tail between 10-24cm in length. Their lifespan is around 2 years but anywhere between 1-3 years is common.

On average a domestic cat is around 3.5-5kg in weight, 45cm long with a 25cm tail. So it is clear that a Brown rat, although large, is not really ‘cat sized’. The big ones may be very small kitten sized occasionally, but definitely not cat sized. 

The reason they are making the news is that as more food and waste is left outside and in the environment, these rats cleverly take advantage of the situation and readily gain weight. So a lot of the Brown rats seen in the environment are the largest size they can be, and when people are expecting rats to be ‘a bit bigger than mice’, they get a shock when a ruler length animal weighing half a kilo pops up!

So if the Brown rats aren’t cat sized, which rats are?

You may be surprised to know there are over 70 different species of rats! In the UK we don’t have any wild rats we could accurately describe as ‘cat sized’, but larger rat breeds do exist elsewhere in the world.

1) The Northern Luzon Giant Cloud Rat

This rat is only found in the Philippines, specifically in the northern and central parts of the island Luzon. Its body can reach 38cm in length, with a total length of around 75cm including its tail. It can weigh between 1.9-2.6kg. This rat could definitely be classed as small cat sized!

2) The Bosavi Woolly Rat

This rat is another very large rat. Weighing around 1.5kg its total length comes in at a whopping 82cm! This species was actually only discovered in 2009, deep in the jungle of Papua New Guinea

3) The Gambian Pouched Rat

As one of the largest rat species in the world, this rat is also famous for being able to detect land mines using scent. They are also trained to detect tuberculosis. What they lack in vision they more than make up for with their incredible sense of smell. They are around 3ft (90cm) long in total length (including their tail) and weigh in anywhere between 1.5-4kg! Definitely cat sized!

4) The Sumatran Bamboo Rat

Last but definitely not least, the Sumatran Bamboo rat rivals the Gambian Pouched rat for being the largest of all the rat species in the world. Weighing up to 4kg, with an average weight of 2.5kg, a total length of around 70cm, and a body length of 50cm! These rats are found in China, Southeast Asia, the Malay peninsula and Sumatra and are definitely at cat size!

Summary:

– Cat sized rats do exist but not (yet??!) in the UK
– Large rats do exist in the UK and these are often the Brown rat
– The largest rats in the world are the Gambian Pouched rat and the Sumatran Bamboo rat

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