Mouse vs Rat: 5 Main Differences Explained

mouse vs rat

Written by Abby Parks

Updated: March 1, 2023

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Key Points:
  • The main difference between a mouse and a rat is its size, with a rat being double the length of a mouse on average. The rat’s tail is also thicker than a mouse’s, and they differ in body shape.
  • A mouse’s habitat includes human homes, garages, burrows under trees, and spots beneath decks. The most common habitats for rats are attics, inside walls, sewers, and cellars.
  • Four of the main mouse species are house mice, deer mice, white-footed mice, and striped field mice. Rat species include brown rats, house rats, Australian swamp rats, and rice-field rats.

At first glance, mice and rats look very similar. They both have a face with tiny dark eyes and twitching whiskers. But, there are a lot of differences between these two rodents. We have looked at the differences between mice vs rats.

The biggest difference is their size. A mouse is much smaller than a rat. In fact, a large mouse is still about half the length of an average rat. Secondly, rats have longer tails than mice. Furthermore, a rat’s tail is thicker than a mouse’s tail. Another difference between these two animals has to do with the size and shape of their poop.

Learn more about the differences between a mouse and a rat so you can recognize one when you see it.

Comparing Mouse vs Rat

Size12 ounces to 1.5lbs.0.5 ounces to 3 ounces
HabitatAttics, inside walls, sewers, cellarsHomes, garages, burrows under trees, beneath decks
DistributionUrban areas in the midwestern and eastern part of the United StatesRural areas of the mid-western and eastern United States
BodySmall ears and a large head, coarse dark brown or multi-color (white, gray, black) furA small face and head with large ears, pointy, triangle-shaped nose, smooth fur in gray, brown or black
PoopDroppings are black and shaped like elongated ovals. They measure around ¾ of an inch. These rodents leave behind 20 to 50 droppings at one timeSimilar to black grains of rice measuring about ¼ inch long. They leave behind up to 100 droppings at a time
LifespanUp to 2 yearsUp to one year
TailThick, hairless with a scaly textureThin and covered with hair
Litter Size5 to 10 babies, also called pups3 to 14 pups
DietPractically anything!Seeds, fruit, bread crumbs
Meat, bread, plants, seeds
Number of species60Hundreds
Kept as petsYesYes

The 5 Key Differences Between a Mouse and a Rat

Physical Size

The most noticeable difference between a mouse and a rat is a mouse is smaller. The body of a mouse can measure 3 to 4 inches in length. And, a mouse’s tail is equal in length to its body. Alternatively, an adult rat’s body is about 9 to 11 inches long with a tail measuring 7 to 9 inches. A mouse can weigh up to 3 ounces making it a lot lighter than a rat at 1.5 pounds.

Number of Species

Another notable difference between a mouse and a rat relates to the number of species. A comparison shows there are many more species of mouse. In fact, there are hundreds of species of mice and 60 species of rats.
Some species of mouse include:

  • House mouse
  • Deer mouse
  • White-footed mouse
  • Striped field mouse

Some species of rat include:

  • Brown rat
  • House rat
  • Australian swamp rat
  • Rice-Field rat

Rat Poop vs. Mouse Poop

Rat poop and mouse poop have different appearances. This is an easy way for someone to tell which type of rodent they have in their house without seeing the animal.

Rat poop is larger than mouse poop. Rat poop is black with an elongated oval shape measuring about ¾ of an inch. It can leave behind up to 50 droppings.

Alternatively, mouse poop looks like a black grain of rice about ¼ inch long. They can leave as many as 100 droppings at one time.

Tail Appearance

Mice and rats have different types of tails. A mouse’s tail is thin, long, and covered with hair. The hair on its tail is usually the same color as its body.

A rat’s tail is long, thick, and scaly. A rat’s tail is hairless.


The diet of each of these rodents is another difference that sets them apart. Rats are known to eat almost anything. They go through the trash and eat leftover sandwiches, fruit, eggs, meat, and more. Also, rats may eat plants and seeds. This makes it easy for a rat to find food.

A mouse eats seeds, fruit, and plants. They may nibble on bread crumbs, but they don’t have as much on the menu as rats!

Dealing with Mice and Rats as Pests

While it’s beneficial to better understand wild animals, they can still pose problems for humans, and at times, should not be allowed to share living quarters. An interesting fact about laying traps for mice or rats is that the two animals have different behaviors when encountering one.

Mice are curious creatures, so will not be afraid to approach a newly laid trap in their quest to figure out what the contraption is. Rats, on the other hand, are more cautious. If you are wanting to lay rat traps in your house, it’s best to first lay the trap out without setting it. When the rat checks it out and finds that it brings no harm, it will more likely be caught once the trap is actually set.

When trying to rid your home of rats, it’s important to inspect your house to figure out where they are, sanitize areas where you find them as best as possible, and set up exclusion tactics. Rats are easier to exclude from your home than mice, as they are bigger. All openings in your house greater than 1/4″ should be sealed. The next step would be setting traps or baiting them.

Some techniques for getting rid of mice include using essential oils like peppermint or clove oil soaked in cotton balls, strategically placed. Getting a pet cat is also an option. Packing tight spaces that mice could enter with steel wool is another tactic that can help, or you can block those spaces with duct tape. And of course, trapping or baiting is another way to rid your house of wild mice.

Do Mice or Rats Make Better Pets?

White rat

Many pet lovers find rats to be adorable companions.


Though they may be an unwelcome sight when uninvited into your home, both mice and rats can make wonderful companions for rodent enthusiasts. Caring for each comes with its own challenges and rewards that require research, time, and effort on the part of a prospective mouse or rat parent.

Mice tend to be much more independent than rats, so they will not require a lot of hands-on attention. Just be sure they have access to dry food and clean water at all times, clean their enclosure of droppings regularly, and give them toys to exercise with and your mice will be as happy as can be! Rats, on the other hand, require a bit more one-on-one time with their owner, but because of this, they can form bonds with their caregiver that are much more personal than those forged with mice. With the right amount of patience and training, these amazingly intelligent creatures can even learn tricks!

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About the Author

Abby Parks has authored a fiction novel, theatrical plays, short stories, poems, and song lyrics. She's recorded two albums of her original songs, and is a multi-instrumentalist. She has managed a website for folk music and written articles on singer-songwriters, folk bands, and other things music-oriented. She's also a radio DJ for a folk music show. As well as having been a pet parent to rabbits, birds, dogs, and cats, Abby loves seeking sightings of animals in the wild and has witnessed some more exotic ones such as Puffins in the Farne Islands, Southern Pudu on the island of Chiloe (Chile), Penguins in the wild, and countless wild animals in the Rocky Mountains (Big Horn Sheep, Mountain Goats, Moose, Elk, Marmots, Beavers).

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