Difference Between Pet Rat vs Mouse: Which One Should I Get?

I often get asked this question ‘What is the difference between a pet rat and a pet mouse?’ So I decided to do some research and here is what I found out.

Rats are significantly larger than mice, they have bulkier faces whereas mice have a more narrow triangular face. Rats feet are proportionally bigger and bulkier than a mouse. Male and female rats need to live in same-sex pairs or groups as they are social animals. Whereas female mice tend to be kept in groups of 3 and male mice need to live on their own as they are territorial and will kill each other.

Most people think mice and rats are very similar if not practically identical, but the truth is there are many differences between the two. It is important to know these differences before making a purchase, so you know what to expect when you bring your new rodent friend home.

The following article will address all the majors differences between the two types of rodents.

The Differences Between Rats and Mice

Mice and rats can be mistaken for one another if you do not know a lot about them, but with a little knowledge, it is easy to tell them apart solely based on appearance differences such as size, facial structure, and tail type. Beyond appearances, mice and rats are actually two very different animals.

For instance, while rats will want to spend lots of time outside of their cages and interact with you, many mice are perfectly happy living most of their lives inside their wire worlds. As you learn more about the differences between mice and rats, you will be surprised that so many people can get them so easily confused.

Before you run to the pet store (or a quality breeder or rescue) to bring home a pet rat or pet mouse for yourself, your kids, or your friend, it is important to know what you are getting into. Read through this article so you can make an accurate decision on which one, if any, you want to bring into your life for the next few years.

Appearances and Habits of Pet Mice and Rats

Rats and mice may look very similar if you are only seeing them scamper around, but when you bring them home as pets, you will begin to see the clear differences in appearance.

First of all, they have very different sizes. Mice are small and around three inches in length. On the other hand, rats are larger measuring about 10inches in length. The larger size of a rat actually makes it easier to handle than mice who are small, nimble and fast. Rats also enjoy being handled, a mouse would rather run around and explore.

While size is one of the first indicators, there are many more appearance differences you can use to tell the difference.

Both rodents are considered nocturnal animals, but if you get a pet rat, it may adapt to your sleep schedule and begin to be more and more active during the day; this is really good for those who want to interact and play with their pet a lot.

On the other hand, mice will not easily readjust their sleep schedule. This means you will want to let a pet mouse sleep throughout the day when it wants, and you will have to put up with the noise when it wakes up at night as they like to run on their wheel, and you are trying to sleep. Keep in mind, that both animals are naturally nocturnal and it is not recommended that your force a sleep schedule change with either, your rat just might naturally adjust.

Rats and mice have different facial structures. The snout of a mouse is very triangular; it comes to a point at the nose. Additionally, mice have very long whiskers sprouting out from the sides of their faces. On the other hand, rat’s snout, while still somewhat triangular, is a lot bulkier and blunter than that of a mouse.

Mice also have larger/floppier ears when compared to their bodies. Dumbo rats do have ears similar to that of a mouse, but a mouse’s ear will still seem larger in comparison to their body.

The final significant appearance difference is their tail. At first glance, they may appear very similar, but they are actually quite different. They both have long tails, but a rat’s is generally larger in width and is almost always completely hairless. Not only is it hairless, but it almost feels scaley if you were to run your hand along its tail.

On the other hand, mice generally have long fairly thin tails, and they are covered in hair. You will probably have to get closer to a rodent, or perhaps even touch it, to identify it through its tail alone.

One main appearance factor to keep in mind that is similar between mice and rats is their coloring. Both rats and mice come in a variety of different colors and very similar colors at that. Because of this, you will rarely be able to tell the difference through the coat alone.

It is worth noting that a rat, especially a male rat, will generally be greaser as they can secrete what is known as buck grease. Buck grease is basically excess skin oil that is harmless and almost odorless.

Rat vs Mouse Behavior


Mice are social creatures, however, male mice are extremely territorial and will be aggressive to each other which will result in one killer the other if they are housed together. For this reason, you can only keep male mice on their own. This could be a good option if you are only allowed to get one pet.

Females, on the other hand, should be kept in pairs or groups of three so they have a more natural living environment.

You should also make sure you have a large enough cage that every mouse can have their own space. (Be prepared that male mice will mark their territory a good bit, especially in the beginning.)

Mice may be aggressive, skittish, or both when you first bring them home as they are not adjusted to their environment. With a little time and patience, however, they will begin to calm down, and that is when you can start to get them used to interacting with you.

To do this, you should start spending time near their cage and talking to them (quietly so you do not scare them or stress them out) so they can get used to our voice and presence. When they start to seem relaxed with you near and perhaps even a bit curious, you can start feeding them treats from your hand.

Once they start eating from your hand, they may start climbing on you, or you can try picking them up. Never squeeze the mouse tightly, but rather scoop it up, and do not hold it high up in the air as a large fall can seriously hurt your mouse.

It is important to keep in mind that while mice may climb on you, some enjoy time exploring outside the cage (only if you make it mouse proof and safe first), and eat out of your hand, they do not need as much attention and may not even enjoy as much as rat’s do.

They are social with each other but can be completely happy spending most of their time in their cage, playing and living amongst themselves. This can make owning a mouse easier and can be really enjoyable for those who primarily get their enjoyment from watching, not doing. If you want to spend lots of time holding and playing with your pet, a mouse may not be the best option for you.


Rats are also very sociable friendly creatures and require at least one other rat mate to be happy (you can keep rats in larger numbers if you introduce them slowly and safely.) Therefore, rats need to be kept in same-sex pairs or groups to provide a more natural social environment to live in, that goes for male and female rats. You can find out why rats need to live with their own here, in another article on our website.

Due to this, most quality breeders, rescues, and pet stores will not sell you only one rat at a time, even if you already have other rats at home, because having a ‘friend’ will make the transition significantly less stressful.

Rats are playful, and one of the ways they play is through wrestling and play fighting – this behavior is perfectly normal and helps establish their complex hierarchy with their group. As long as they are not being aggressive and no blood is being drawn, it is okay for them to wrestle and fight.

Additionally, rats will be very social with you. Rescues may take some time to adjust to you and take some trust training, but when they warm up, they will love playing and cuddling with you. Rats you get from breeders will probably already be socialized and love to be around you right from the start.

Male rats are generally more cuddly, and female rats are more playful, but both will require at least an hour outside of their cage a day—and more if possible. This means that they are a great pet if you want to interact with them a lot and form a close bond, but you should remember that it also means caring for them will take significantly more time and energy.

Rats are also extremely intelligent. This means they will learn who you are fairly quickly, and rescue rats will probably know you saved them. They are so intelligent that many people compare them to dogs. This means that it is even possible to litter train a rat, making cleaning a lot easier of a process. Of course, when training a rat, you have to have lots of patience and should only ever use positive reinforcement, not punishment.

They experience emotion, are curious, love to explore, and can even learn tricks. Pet rats are also observant, and it’s their strong sense of empathy and compassion that sets them apart from the other animals we keep as pets.

Due to rats’ need for socialization and stimulation, they also can get bored very quickly. A few signs that your rat may be bored include over-grooming and bar chewing. If you notice these signs, you need to either up the amount of time you are spending with them, get them more toys, or you most likely need to do both.

You can find 22 creative ideas to entertain your rats here in another article I wrote.

A bored rat is not a problem you can just ignore as boredom in rats can lead to more serious health problems. If you are not prepared to provide a rat with all the stimulation it needs to live a happy and healthy life, it may not be the best time for you to bring a rat home.

What Is Cost Difference Between Mice and Rats?

Truthfully, owning a mouse and a rat will cost similar amounts. You will have to buy a cage, food, bedding, buy a cage, food, bedding, toys and other important expenses for both a mouse and a rat.

A lot of what it will cost to actually buy that rat or mouse depends on what kind of cage you are getting as this tends to be the single largest outlay. Rats will need at least two and half cubic feet per rat whereas mice can live in smaller cages.

Please also keep in mind that well its probably cheaper to buy a rat or mouse from the pet store at first glance, however, these animals have more than likely been bred in large quantities and not very nice conditions – this could lead to expensive vet bills.

If you can buy from a quality breeder, that is a better idea. Most pet stores breed for the quantity, not quality, so animals from a pet store are more likely to have health problems and be less socialized.


Rats and mice are both great self-groomers. This means that they will keep themselves clean, so you do not have to bathe them (and usually they would not enjoy a bath anyways) unless your vet instructs you too for a specific reason.

Rats, especially male rats, are known to become greasier than mice. While this is not harmful and does not even smell all that much, some people may find this gross.

As far as the cages go, rats and mice start on fairly even playing fields – it is worth noting that male mice are very territorial, so will probably pee a lot, all over the place, in the beginning. With training, however, rats can become cleaner than mice as it is possible to litter train rats. You are welcome to try to litter train your mouse, but you most likely will not have any luck.

Lifespan Of a Rat vs Mouse

One of the biggest deterrents for potential rat and mice owners are the life spans. Pet mice generally live around one to two years, and while pet rats usually have another year beyond that (on average two to three years), both are relatively short compared to other pets.

However, mice and rats can make such fun and fulfilling pets that it is worth it for many people to spend that time enjoying it, even if they don’t actually live that long.

Additionally, do not let yourself think that the time span is short enough that it is not a real commitment. Taking on an animal’s life for even two years, let alone three is a big commitment. You have to be prepared to buy them what they need, clean their cage, spend time with them (especially if they are a rat), etc.

A lot in your life can change in three years. You can get married, have kids, go off to college, and go through other major life changes. Before buying a rat, try to look towards the future for what changes you foresee happening and make sure it is a good time for you to be bringing a rat or mouse into your life.

Can You Keep a Mouse and a Rat Together?

No! While rats are very sociable and love to live with other rats, if you put another small rodent in the cage with them, it is likely that the rat will kill and eat it. In fact, if you own both, you should not have them out and around each other at the same time and possibly not even house them in the same room.

Mice and rats have excellent senses of smell, so it may stress them out just to smell each other if their cages are kept in close proximity. Of course, if you want to own both, have space, are financially ready, and have the knowledge necessary for proper care, you can own both. Just keep them in separate cages and in separate areas.


Both rats and mice make great pets that can bring a lot of joy into your home, and which one will be best for you really depends on personal preference.

If you would rather have a smaller pet, that is fairly self-sufficient and likes to be watched more than interacted with, a mouse is probably the better choice for you.

On the other hand, perhaps you would rather have a pet that is larger, will form fairly quick bonds, affectionate, and is possible to train to do tricks; a rat is probably what you are looking for.

Also, remember that just because you decide whether or not you want a rat or a mouse, that does not mean you should get out your wallet and stop researching. Research farther into different types of mice and rats to figure out more about what you specifically want. The last thing you want is to bring home an animal and end up not being happy with your decision.

Whether you bring home a pair of mice or a pair of rats, enjoy the joy they will bring into your life to the fullest.

Darren Black

I'm Darren Black, the owner, and author of AnimalKnowhow.com. I am from Scotland, United Kingdom and passionate about sharing useful information and tips about properly caring for an animal's wellbeing.

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