There's a lot more to know about keeping mice as pets than many people realise. There are loads of resources on the web about caring for your pet mouse, but who ever heard of too much information? So I've decided to make my own how-to of keeping mice, gathered from 15 years of experience, as well as from other resources along the way. If there's anything I've missed that you think should be included here, or you have any questions regarding keeping mice, please feel free to email me.

Before I start, I can't emphasise enough the importance of finding a good small animal vet before you purchase your first mouse. Mice can get sick very quickly, and you don't want to have to play games, running around to different vets, when you have a sick pet. People will probably laugh when you tell them you spent $100 on a vet bill for your mouse, and ask you why you don't just buy a new one. But stay strong. A mouse may be small, but it is just as important as a cat or dog - or child - in your family. If you're not prepared to spend money on the health and wellbeing of your mouse, please do not get one. It's just not fair on the small creature that relies on you.

Why a mouse?
One mouse or two? Boys or girls?
Can I keep multiple males together?
Where do I get a pet mouse?
What's the difference between a feeder mouse and a fancy mouse?
How intelligent are mice? Can I teach them tricks?
How do I choose my new mouse?
What kind of cage should I get?
How big should my cage be? Cage Calculator.
What kind of litter and bedding are best?
Would my mouse like some toys?
What should I feed my mouse?
I want to breed my mice, what do I need to know?
I think I bought a pregnant mouse, what do I do?
How do I care for a pregnant mouse?
How do I care for and raise baby mice?
I have found a litter of orphaned wild mice, what do I do?

Why a mouse?

Mice make excellent pets! Ok, I may be a tiny bit biased ;) They're really easy to keep, aren't too expensive, are hilarious to watch, calming and enjoyable to play with, and make great pets for responsible children over the age of 6. They come in an infinite array of colours and coat types and, after all, who can resist those little twitchy noses! Mice only live to around two years, so they make great pets for people who aren't quite ready to commit to a cat or dog, or those who live in apartments and can't have a bigger animal, but it also can be really sad to lose a beloved family member after such a short time. One thing is guaranteed - you will get addicted!

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One mouse or two? Boys or girls?

Mice are social animals, so it is always better to get two or more mice to live in a community cage. This is easier with females, as males are territorial and will often fight. Even older females can be difficult to introduce to new babies, it depends entirely on the personality and preference of the mouse. I find that males are often friendlier than females and can make better pets, but this may be a product of living alone. Males also smell more than females.

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Can I keep multiple males together?

Yes. But it can be tricky. The key to keeping males together is to purchase two brothers at the same time. As long as they are never separated, they should live together relatively peacefully. There will usually be scuffles and dominance struggles, but as long as no blood is drawn, there is no need to separate them. If your males do seem to be at war more than peace, try and make the cage bigger, and include a house, wheel and food dish for each male so they don't feel the need to fight over territories.

I have successfully kept groups of two, three and four boys together in appropriate-sized cages and have even separated one member of the group to breed. I found that going half a day with the boys and half a day with the girl for a few days both kept him familiar enough in the bachelor cage so as not to be attacked, and managed to get his girl pregnant. I would only do this with a group of boys that were very well established, and these boys very rarely fought.

One last word, boys tend to go through a sort of puberty at a few months old. Some groups can get quite aggro at each other, and I've had moderate injuries sustained during this hormonal period. I find that less frequent cage cleans help as they don't need to constantly re-establish territory, and treating both mice equally. If one gets picked up, the other gets picked up. Multiple bowls etc as stated above is also useful.

I am yet to see males who cannot be convinced to live together, as long as these guidelines are followed. I know other people have had different experience, though, so it comes down to a common sense decision. Don't risk the lives of your mice through stubbornness.

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Where do I get a pet mouse?

Rescue. What better way to start your pet mouse obsession than to save a life? Ask at a local animal shelter if they keep abandoned mice. Many won't, but should be able to direct you to a small animal rescue. There are often young animals available for adoption, as many females are abandoned already pregnant. Many breeders also rescue and rehome abandoned mice.

Breeder. Finding a mouse breeder is a really good way of ensuring you a well-adjusted, healthy pet. Search through Rat & Mouse Clubs, on the Internet, or publications listing local breeders that are distributed to vets and animal shelters. Often the best way to choose a baby mouse from a breeder is to attend a Club Show and choose one yourself. Even better, if you can arrange it, visit the breeder at their home and ask to see where the mice are kept. If the breeder is worth his/her salt, they will also ask you a dozen questions about why you want a mouse, how you will keep it, and so on. Watch out, though, because some breeders are no better than mass-producing mouse factories, and have little regard for the health and temperament of their babies. If something doesn't sit right, or you visit their mousery and it's unclean, overcrowded or their animals look sickly, then find another breeder. It's up to you to make sure they're doing the right thing too.

Pet Shop. Perhaps the easiest place to find a mouse is your local pet shop, but this is hardly the best. Some pet shops do keep healthy animals on the right litter and give the right advice, but they are few and far between. Too often I see mistreated, malnourished animals in pet shops - and that's the animals that they're selling for pets, not food. Mice that are sold purely as food for snakes are rarely happy, healthy animals, and are usually kept in mixed-sex bins. This means that if you do decide to purchase a female from a feeder bin, she will almost definitely be pregnant. If you feel you have no option other than to get your mouse from a pet shop (or fall in love with one particular mouse when passing through - we've all done this), then watch out carefully for the checklist below.

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What's the difference between a feeder mouse and a fancy mouse?

A mouse is a mouse is a mouse. Whether it was bred with the intention of being lunch or someone's pet doesn't make a difference - it's not a different species or anything. Generally, but not always, feeder mice are albino and often they are bred to have larger litters to better feed your snake. Generally they aren't handled very much, therefore they usually aren't as tame as those destined to be pets. Depending on the source (ie. a bad feeder breeder), they can be quite inbred and have problems. But, then, some fancy mice breeders are just as bad with this, and some feeder breeders have excellent practices. So, in conclusion, that's a whole lot of generallys, usuallys and oftens. Just find a mouse you like and go with it :)

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How intelligent are mice? Can I teach them tricks?

I find my mice to be very intelligent, for a small animal. I've heard it said that they are more intelligent than hamsters and gerbils, though we don't get those here so I can't say from personal experience. When I enter the room, my mice will almost always pop out to say hello and often rally at the cage door waiting to be paid attention to. I have heard of people training their mice to do simple tricks, come to their names, etc with the use of large amounts of repetition and treat rewards. I haven't done this myself as I prefer my mice to behave as they want to, not as I think is cute. Remember, mice are used in laboratories all over the world to study behaviour, run mazes, hit coloured buttons that lead to food - all this indicates a level of intelligence.

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How do I choose my new mouse?

Regardless of whether you choose a pet mouse from a rescue, a breeder or a pet shop, there are certain things you should always ensure.

• The animals should be alert and healthy-looking, with no breathing problems, sneezing, injuries, excessive scabs or scratching, weeping eyes, no sign of diarrhoea, with a full, healthy coat.
• The enclosure should be suitable, that is, not overcrowded, with ample hideaways and clean food and water, the area should be relatively clean of waste and should not smell too much. Check what type of litter they're being kept on (I'll go into detail on this later).
• The mice should be kept separated by sex (if they're not, females will likely be pregnant) - in some places, not separating males and females is actually against the law, so this is important.
• Ask whether they sell the mice for snake food - if they do, it tells you they probably won't put a lot of care into keeping the mice they have happy and healthy.
• Ask about the history of the mouse - where did it come from? Do they know anything about the parents? If so, were they healthy and long lived? How old is it? If female, was it separated from its brothers by 5 weeks old, to ensure it is not pregnant? If it is from a breeder, does it have a pedigree?
• And finally - perhaps most importantly - make sure you handle the mouse before purchasing it. The most beautiful, healthy mouse is the world will do you no good as a pet if it is not friendly.

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What kind of cage should I get?

Wire cage. Probably the most common type of cage you'll find; there are hundreds of different brands and types of cage you can buy from pet shops or online. I prefer these cages as there is ample ventilation, the mice love climbing on the wire walls, and it's super easy to attach toys all over the place. The only down side I can think of is that some of these cages have only a tiny access door, which can make it difficult to catch a less friendly mouse.

Aquarium. Aquariums can make excellent enclosures for your mice because they come in very large sizes, are easy to fill with toys and easy to keep clean as no smells will sink into the glass. They are also good for people with cats, as they are too heavy to be knocked over, and with the right lid, will safely withstand and curious cat on top. The main down side to an aquarium is that there is little ventilation and in the summer can literally cook your babies if you don't take the right precautions. Using a mesh lid can allow some circulation, but make sure the mice can't chew through it - you'd be amazed how high they can jump!

Plastic S.A.M/Habitrail type cage. These cages are really popular with the pet mouse keeper, though I wouldn't want to have more than one to clean. They are great to look at, colourful and fun for your mouse, but all those tubes and compartments get really icky really fast. After a few weeks of scrubbing pee out of those tubes, you might change your mind about how cool they are.

Wooden cage. Wooden cages aren't around as much as they used to be. I know some people use them as breeding boxes because they are solid and dark, making a mother mouse feel more secure, though the pee does seep into the wood over time, and your mice will chew at any exposed corner. I wouldn't recommend them for use over extended periods.

Home-made. Certainly the cheapest type of cage, many people forgo the expensive pet shop bought enclosures for a simple plastic tub. Basically, you buy a large tub from Kmart, cut out the top and maybe one side, and cover with fine, metal mesh. Then, drill holes for the water bottle or hanging toys, and fill with whatever your heart desires! For full instructions on how to make one of these cages, search on Google - there's plenty!

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How big should my cage be? Cage Calculator.

As a general rule: the bigger the better! Below is my Mouse Cage Calculator (with assistance from Ratz R Us Rat Cage Calculator, credit to Nicola McCallion).

Notes Before Use:
1. If you have a cage with shelves, ensure that the mice actually use the shelves before including them in calculations.
2. If your cage does not have any shelves, then leave the value in the three shelf columns below as 0. Only the base width and depth (not height) are required.
3. This is a guide only! Please use your common sense when buying a cage (or more mice), and if you're not sure, get less mice rather than more. The more mice you pack into a cage, the more frequently it will need cleaning, and the higher the danger of disease or injury.
4. This Cage Calculator is only new, so I am looking for any feedback you may have. If you get a result you would not expect, or have any questions or suggestions, please email Katy.

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What kind of litter and bedding are best?

Recycled paper pellets. This is what I use for my mice (the brand is called Breeder's Choice here - in the US I believe it is Yesterday's News) as it is relatively cheap, easy to obtain (the supermarket has big bags) and totally safe. There's no toxins or aromatic oils to worry about, it's safe to be chewed on, and my mice love digging through it. There are also types of compressed paper litter (such as Healthy Pet, or Carefresh in the US) that looks like little chunks of mashed paper pulp. This is even softer on little mice feet, and it's quite light, so mice tend to enjoy making tunnels underneath it if given enough. I prefer the Breeder's Choice as I found it had slightly better odor control, and is a lot cheaper.

Wood stumps/shavings. I would advise to stay far away from any sort of wood litter product. Many people say it's fine to use pine as long as it's kiln-dried, and I have known people to do this successfully, but personally I think it's still risky. The aromatic oils in pine and cedar irritate the respiratory systems of small animals, and will most likely cause mycoplasmosis (a respiratory disease). This can be treated, but in some individuals it can stay with them for the rest of their lives. The only safe type of wood litter is aspen, but this can be hard to find and expensive. If your pet shop or breeder keeps their mice on shavings, ask them what type it is. If they don't know, it's probably pine, and any mice you buy from them will most likely come with myco. I have experienced this on multiple occasions and it is notoriously difficult to cure.

Kitty litter. Clay-based kitty litter is another no-no. The clay is dusty and can also irritate little mousey lungs. That said, before I knew better, I used kitty litter for all my mice (this is many years ago) and never had so much as a sneeze. Again, it's a case of better safe than sorry - stay away from it if you can.

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Would my mouse like some toys?

Simple answer: Yes! Mice are very active animals and crave stimulation. There are plenty of different toys available at pet shops (check the bird toy and cat toy section as well). Anything that is safe to be chewed at (hard plastics are generally ok, but stay away from soft rubber or anything that looks like it could be eaten) will be played with.

Tubing. Companies like S.A.M and Habitrail make addon tubes and houses to go with their cages, but you can buy them separately and just use them as tunnels in the cage - mice love tunnels. For a cheaper idea, go to a hardware store and buy PVC piping to use instead.

Toilet rolls. Tthere is little that beats the good old toilet roll. Pile a few together to make a toilet roll castle, or hang them from the walls or top of the cage with thin wire. They'll get chewed to pieces for nesting material, and just for fun. Easy to replace them whenever they get destroyed!

Ropes. Thick ropes strung across the cage are an exercise in balance. You can buy sturdy colourful ropes from pet shops as a bird toy that attach to the cage bars, or just make one yourself.

Wheels. There is one toy that must never, ever be passed up - the wheel! No mouse house is complete without the trusty wheel. I prefer the type that is enclosed, so mousey doesn't have to worry about getting his feet or tail caught in the bars.

Mouse balls. Another thing that many mice enjoy is the mouse ball. Pop him in and watch him run around the room in the safety of the ball. Some mice don't 'get' balls - don't force them. Most will love it, but let them tell you whether they do or not before sticking them in every afternoon.

Food toys. Loosely scrunched up balls of paper with some food in the middle make for hours of entertainment. Or thread bits of food onto some thin wire and string it across the cage for some climbing fun. Cat balls also sometimes have room for a treat or two to be pushed inside, and your mice will go nuts trying to get it out.

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What should I feed my mouse?

Mouse muesli. You will find basic seed mixes sold at the supermarket or a pet shop. Many people simply give this mix, and it is suffcient to keep a mouse happy. However, I like to add a few things to make the mix more interesting, and a little healthier and balanced.

• 5 parts seed mix
• 2 part plain rolled oats
• 1 part dry cat/dog kibbles
• 1 part uncooked pasta
• handful of rice or wheat puffs (get them from the health food section, look out for no sugar or preservatives)
• handful of split peas
• whatever else i have at the time (a little dried fruits or coconut, crushed up crackers, etc)

Lab blocks. A complete balanced diet for a mouse - it's what they're fed in research labs, which is why they're called lab blocks ;) They are also terribly boring. If you want to use lab blocks (I sometimes do - they're cheap and easy and good for your mouse) make sure they get plenty of variation in their treats and fresh food, as outlined below.

Fresh fruits and veggies. Some mice love the occasional fresh fruits and veggies - others don't. Experiment by putting in little slices of carrot, broccoli, capsicum, cucumber, celery - be creative. Lettuce is generally a no-no as it tends to give mice diarrhoea. Fruits should be given in moderation as they are high in sugar, but I've found that apple, grapes, pear and melon are quite popular.

Baby food. Good quality baby food (check the ingredients to make sure there's no colours, preservatives, salt or sugar added) is also an excellent treat and I've found that even with mice that don't like fresh veggies, they'll all dig in to some baby food. The best flavours, in my opinion, are the plain veggie ones, or the meat and veggie dinners. Plain egg custard is also a popular one. A good way to get your mouse to like you is to put a bit on the end of your finger and let him lick it off. Prepare to be nibbled, though!

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I think I bought a pregnant mouse, what do I do?

It happens to almost anyone who buys a female mouse from a pet shop, and it's a risk you need to accept if you choose to go that route. Pet shops are notorious for not separating boys and girls, either accidentally or because they don't particularly care. I've even come across more than one pet shop who purposely leave boys and girls together so that any female mice they sold would have babies to be returned to their shop as more stock.

It's obviously not an ideal situaiton, as you won't know the history of the mice,

If you're concerned about your mouse being pregnant, there are some things to check for.

• Double check the sexes of your mice. The shop may or may not have sexed them correctly. (I will add some mouse sexing pictures as soon as I make some, for now, a Googling should produce plenty of how-to guides).
• If you find you have mixed sexes, you need to make the decision to return one sex, or separate them into same-sex cages (remove the male ASAP regardless, on the chance that he hasn't gotten her pregnant yet). You cannot keep males and females together for the long run because they will breed constantly (ie. a litter every 3 weeks). This is not only incredibly taxing on the poor girl, but you will have a lot of babies to find homes for.
• If you definitely have only girls, then the next step is to wait 19 - 21 days, which is the gestation period of a mouse. If the 21 day mark passes, no babies for you!
• However, if your mouse starts to look like she swallowed a golf ball (mice only start to show physical signs of pregnancy at about 2 weeks) you might soon have a litter on your hands.
• Note, that many females will get pregnant at the pet shop so even if you do have only girls, you might still end up with a litter.

For more information on breeding mice, see the next section.

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I want to breed my mice, what do I need to know?

Before you do anything, here's a few things to think about:

• Why do you want to breed your mice? There are so many wonderful little mice in the world already, why do you want to make more? If you want more pets for yourself, can you not buy or save some instead of breeding?
• What will you do with all the babies? Mice often have litters of 12 or 15, and can have 20 or more in some cases - can you keep them all? Taking 'surplus' babies to a pet shop is far from ideal, as they may simply end up as someone's dinner :(
• What will you do if your pregnant mouse has a problem during delivery and needs vet attention? It's a good idea to have both a trustworthy vet with small animal experience, and the necessary money on hand, should something happen.
• Do you know the backgrounds of the mice you want to breed? Breeding pet shop mice which are likely riddled with cancer, immune weaknesses or temperament issues is not the best idea. Make sure you know that the mice you choose are from long-lived, healthy and well-temperamented lines with pedigrees that go back at least 3 generations so you don't get any nasty surprises. Knowing their genetic history will also help you plan for what colours and markings your babies will likely be.

If you're still sure you want to breed your mice:

• Female mice become fertile at approximately 5 weeks old, but that does NOT mean it's a good idea to start breeding them at that tender age. The best age to breed a female is from 4 - 8 months old. Make sure she is fully mature and at her adult size before breeding her, or it could stunt her development. Any older than about 8 months is a risk, as older females that have not had a litter before often have fused hips that will make delivery dangerous or impossible.
• You need a male and a female, obviously. If you only have a female, many breeders will be willing to stud out a male. This way, you can ask about his history before deciding. You'll find less people interested in lending a female to breed with if you only have a male, so you may be better off buying a pedigreed female instead.
• Always put the new couple into a clean cage. Females especially can be quite aggressive and territorial towards an interested male, and even if in a different cage, can often be forcefully protestant for the first few days. You'll probably see him going after her a lot and her squeaking like crazy and running away. He won't hurt her, but it can be a stressful time - for the mice, and for you!

Take a look at the next section for more information about the caring for a pregnant mouse.

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How do I care for a pregnant mouse?

Housing: Many people (myself included) separate a pregnant female mouse to raise the litter alone, as it has been known for companions to attack and kill another mouse's babies. I would especially do this if you have a group of 3 or more mice living together, as the situation could prove unpredictable, stressful and dangerous for mum and bubs. However, if you only have two mice, and they live together happily, separating the mum would leave two lonely girls and may not be necessary. The buddy will often act as a nanny, sharing the duties. If you choose to go this route, keep a close eye on the nanny when mum gives birth and make sure she's not showing any aggression towards the babies.

Nesting: You will want to provide mum with plenty of nesting material and a nice safe, dark place to build her nest. I use non-scented, unbleached tissues or toilet paper for nesting, but you can also buy a sort of cotton wool designed for small animals from pet shops. Don't ever use material (unless it's felt), or anything with strings or threads that could twist around little baby feet or heads. Also, try and make sure the cage is in a quiet area of the house where she won't be disturbed too much.

Feeding: Pregnant mice (and all animals) use a great deal of nutrients and energy creating and carrying little lives. They need a good quality, high protein diet, and lots of it. I tend to double the amount of dry mix I give my pregnant girls, and add things like small bits of cooked chicken or tuna, scrambled egg, bread soaked in soy milk, porridge, baby food, etc. You could also add small animal vitamin drops to the water if you'd like to go the full hog, but I rarely do this as I feed a pretty good diet.

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How do I care for and raise baby mice?

The most important thing to remember when you've got a litter is that mother knows best. You have almost no chance of successfully raising mouse babies under about 2 weeks old, and even at that age it's extremely difficult. If you only remember one thing, remember this: Don't stress, she knows what she's doing!

Birth: You'll notice when mum is getting close to giving birth that she'll work furiously on her nest, and usually spend a lot of time in it. If you're lucky enough to be present when she chooses to give birth, don't touch her or the babies, poke around the nest, or disturb the cage at all - just leave her alone to do what she does best. Shortly after birth, you'll start to hear the little squeaks of babies, which are called pinkies at this stage. They will squeak like this almost until they are weaned, and are often also called squeakers :) If you put them close to your ear, you'll also hear that they make small clicking noises which I've never seen mentioned anywhere, but it's my theory that this is either a communication to their mother, or sucking their mouths as if searching for a nipple to drink from.

Cannibalism: It is common for mother mice to kill and eat (or partially eat...) some of the babies. She may do this if the baby is malformed or not healthy, if she's feeling stressed and nervous, or if she has a large litter and she feels she can't raise them all. Usually any culls will happen at or close to birth, but it can also happen up til about 2 weeks. Occasionally you will get a mouse that just isn't a very good mother and will kill or abandon her babies, but this is quite rare. In this situation, the best thing you can do is provide her with a stress-free environment. I would also avoid re-breeding any mouse who did this.

Handling: If mum knows and trusts you, you can start to handle the babies from birth, but if she's new or is a nervous mum, leave them 3 - 5 days, or more if she still exhibits stressful behaviour at that time. Start by gently stroking and moving the babies around in the nest, just to get your scent on them. See how mum reacts. If she's fine, then the next day you can pick them up and cup them gently in your hands. Pinkies haven't yet gained control over their muscles, so they will spasm and pop all over the place. Be very careful not to drop them), and to only hold them over a table or your lap so that if they do fall, they don't fall far. If this does happen, don't panic, pinkies (like human babies) usually bounce ;) It's important to handle the bubs every day, more if you can, to make them nice and friendly. The more they're used to being handled, the better pets they'll make. I've found that the most vital time to handle them loads is the few days before and after they open their eyes - I think it impresses on them more if they see and feel you as the first thing they experience.

Development: At a few days old, babies that will be dark (agouti, black, etc) will start to develop pigment. At 8-10 days they will have velvety peach fuzz (from here they are called fuzzies), and now you should be able to sex them by checking for nipples under their arms along their sides. Their eyes will open at 12-14 days, and by 3 weeks they should be nibbling on solid food and hopping around the cage. At this stage they enter into what's known as 'flea stage'. If you haven't handled them much, or if their parents don't have fantastic temperaments, they will pop out of your hand and leap everywhere. I find that with enough handling, they pretty much skip this stage - but you will need to be careful taking them out of the cage anyway, just in case! At 4.5 weeks, it's time to separate the boys and girls. This is VERY important! If you don't, at about 5 weeks of age, mum and all your female babies will be pregnant! If you're lucky, you've kept track of your boys and girls from your nipple-sexing, if not, you'll need to sex by genitals at this stage because nipples are now hidden in fur. This can be tricky - Google for some sexing pictures.

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I have found a litter of orphaned wild mice, what do I do?

As far as I understand, it is extremely difficult to successfully raise baby mice (whether from a pet or wild mouse) if the baby's eyes aren't open yet. They require frequent feedings and stimulation to the point that you will get very little sleep. Even with that, the chances of them surviving are still low. If the eyes are open, they will still need nutrients via a milk supplement, but they should be beginning to eat solid food on their own and have a higher chance of survival.

I don't have any experience with this personally, but here's some handy sites:

Rat & Mouse Gazette: Caring for Orphaned Baby Rats or Mice

Hand Rearing Mice

AFRMA: Caring for Orphans