What is the difference between a rat and a mouse? Many people (and that included me before writing this article though) think that there is no difference between a rat and a mouse. We use these words interchangeably and without a problem call mouse a rat and vice versa!

In this article, you may see some similarities in both rats and mice because they belong to the same family but some key differences are important to note.

Next time you encounter a rat or a mouse, we expect you to use correct terminology because even they have brains (read: hearts) and they can feel bad if you use incorrect terminology. So, learn the difference between a rat and a mouse because some extra information never hurts.

Before learning the difference between a rat and a mouse. Let’s learn something more about rats and mice in general.

A Basic Understanding of Rats

a brown rat
A Brown Rat | By AnemoneProjectorsBrown Rat (Rattus norvegicus) Uploaded by Snowmanradio, CC BY-SA 2.0, Link

Rats are of medium size and they have long tails. Rats belong to the genus Rattus. There are two popular species of rats – brown rats (Rattus norvegicus) and black rats (Rattus rattus).

These are popularly called true rats or Old-World rats. These rats originated in Asia. Male rats are called bucks and unmated females are called does. Pregnant or parent female rats are called dams and infant rats are called pups or kittens.

Mischief (and rightly so!) is the name of the group of rats. Rats are excellent swimmers.

The rat species depend on opportunistic feeding and they live near humans. Because of this habit of living near humans, they are called commensals.

Most of the species of the genus Rattus are now endangered thanks to the three species of the same genus – brown rat, black rat, and Polynesian rat.

Did you know that humans have employed rats? Yes, rats work for humans. Demining, sniffing of gunpowder, animal-assisted therapy, acting, etc. are some of the works that these rats do for us.

A Basic Understanding of Mouse

house mouse - difference between rat and mouse
House Mouse | By George Shuklin – Own work, CC BY-SA 1.0, Link

A mouse is characterized by a pointed snout, a body length tail, and small rounded ears.

It belongs to the genus Mus. The popular species of this genus is a common house mouse (Mus musculus).

The mice are mostly used as pets or laboratory animals. The poor white rodents that researchers use are mice. They are mostly nocturnal and have poor eyesight. But, they overcome this shortcoming with their amazing sense of smell and hearing.

The mice are famous for building burrows when they are in the wild. A mouse, whether present indoors or outdoors, is an excellent swimmer.

We will stop right here. We don’t want to go into further details because we will be creating dedicated facts sheets for them.

It is time for us to learn the difference between rat and mouse.

Difference Between Rat and Mouse

If you speak biologically, rats can be differentiated from mice by their size. If there is a small muroid (muroid is a superfamily of rodents which includes voles, rats, hamsters, mice, gerbils, etc.) rodent its common name includes the word mouse and if there is a big muroid rodent, the common name includes the word rat even though that particular species is not a rat or a mouse.

Let’s get to the difference between rat and mouse in details!

Difference Between Rat and Mouse – Physical Characteristics

A mouse has a slender body. The body’s length is the same as the tail’s length. The length of the mouse (including the tail) sums up to 60 to 200 mm.

Mice have large ears. They are either light grey or brown and have a lighter shade of fur on their bellies. Their weight is mere 25 grams.

A rat, on the other hand, has a thick body. The tail is not as long as the body. The total length of the rat (including its tails) is around 390 mm.

Rats have small ears and a blunt nose. They have paler colors underneath their tail and not under their bellies. Adult rats can weigh up to 500 grams!

Note: Here we are talking only about brown rats or Norway rats. We are excluding black rats because they have mix characteristics of both mouse and rat and they mostly live near ships or ports and not near our homes. Bonus point as they live near ships, they are generally called ship rat or roof rat.

Eating Habits of a Mice and Rats

What Does a Mouse Eat and How?

A mouse prefers cereals. It kibbles the grains and eats mostly the endosperm of the cereals leaving the husk.

The mouse doesn’t need to drink water every day but if available it drinks 3 ml of water. It goes to the same place where food is available.

It is inquisitive and readily eats food which is new to it and as a matter of fact, it prefers new food over the old variety of food.

It visits multiple sources at night and if there is only one source, it visits the place nearly 200 times and gulps down just 20 grams of food every time each night.

What Does a Rat Eat and How?

A rat also prefers cereals. It eats the cereals in such a way that it looks as if it has been chopped. Water is necessary for a rat and it drinks up to 60 ml of water every day.

Just like a mouse, it goes to the same food source again and again.

A rat is suspicious in trying new foods and takes some time in adjusting to any changes in food or its environment. A rat can happily devour a mouse.

Difference Between Rat and Mouse: Living Space

A mouse lives on the ground. When it is indoors, it occupies any space that is usually not disturbed by others. It builds its nest in places like attics, furniture, boxes, under floorboards, etc.

It shreds any paper available to make its nest cozy and comfortable. It is agile and can climb without any problem. When it is outdoors, it makes burrows in the ground.

A mouse is usually not found in places where rats rule because it is scared of getting killed!

A rat lives on the ground. When it is indoors, it lives in crevices that are big enough, cavity walls, attics, lofts, etc.

It shreds whatever possible to make its nest warm and comfortable. It makes burrows in the soil, especially near a water source.

In urban areas, sewers are filled with rats.

You May Also Like:

-- Difference Between Poison and Venom
-- Difference Between Affect and Effect
-- Difference Between Osmosis and Diffusion
-- Difference Between Travelling and Traveling
-- Difference Between Respiration and Breathing

Difference Between Rat and Mouse Droppings

A mouse’s droppings are 3-8 mm in length. They are black and granular in shape. The droppings are usually found near nesting areas. It produces 40 to 100 droppings a day.

A rat’s droppings are spindle-shaped (they resemble rice grains) and are 20 mm in length. It produces around 20 to 50 droppings every day.

Difference Between Rat and Mouse Reproduction

Litter size of a mouse is somewhere around 4 to 16. In a year, a single mouse can produce 7 to 8 litters. The infants mature within 8 to 12 weeks to start reproducing again.

Litter size of a rat is 7 to 8 and in a year, a rat can produce only 3 to 6 litters. It takes 10 to 12 weeks for a rat to become sexually reproductive.

So did you get it? Rats and mice (being rodents) have similarities but they do have differences too. Nonetheless, both of them cause infestations and those infestations, if not taken care of at an early stage, may lead to serious financial damages.

Don’t forget that they are carriers of many diseases! Remember the deadly Black Death and be cautious.