Rats PDF Print E-mail

About Rats

Basic Information


The pet rat is a domesticated breed of the brown rat (rattus norvegicus). Rats have been domesticated for over 200 years. Selective breeding of many generations of Norway rats over all those years has produced the domestic rat of today which comes in many different colors and markings. Rats are intelligent, affectionate, clean animals with lots of personality and enjoy spending time with people. They are curious and adventurous. Pet rats – like their ancestors – are very social and should be kept in pairs or more (same sex unless neutered or spayed!).


Rats live in colonies in the wild and therefore should be kept in at least (same sex unless neutered or spayed) pairs as pets. They groom each other, play and sleep (often piled up) together. Since you are part of the rat pack too, don’t be surprised if your rats start grooming you too! They might check your ears, nose, eye brows, lips and teeth. Be proud and enjoy!

Normally, male rats get bigger than females, have coarser fur and can have a slightly “musky” smell (some people describe the smell as warm corn chips). Rats reach puberty at around 5-6 weeks of age, but they reach social maturity at around 5-6 months of age. At this age, male rats in particular start to behave more aggressively toward each other. They shift from harmless play fighting into more serious adult fighting. They establish their hierarchy. This might look scary but don’t interfere unless there are injuries involved. Females have softer fur (sometimes their fur has a pleasant sweet smell). They tend to be more active, hardly sit still and always have places to go. Older rats do calm down, though. Rats don’t see well (especially pink eyed rats). You might see your rat swaying his head from side to focus on an object and to help the rat figure out how far away various objects are. They rely heavily on their nose and whiskers rather than on their eyes. Rats can hear and produce ultrasound. They communicate with each other at frequencies we humans can’t hear. Sometimes you will hear the occasional squeak. As a general rule, audible vocalizations are signs of protest, pain or stress.

You might see your rat grinding his teeth. This is called “bruxing”. Your rat might do it when stressed, in pain or when very content and relaxed. Sometimes, a rat's eyes may vibrate rapidly in and out of the eye socket, a phenomenon called “eye boggling”. This odd eyeball movement often occurs at the same time as bruxing, or tooth grinding. If you witness this, your furry friend is content and happy.

People are often turned off by “that naked tail” (it is actually covered with hair) but it is a useful tool for the rat. It helps balancing and regulating the body temperature. Never pick up your rat by its tail. The skin might actually “de-glove”.

Rats can’t vomit. They have a powerful barrier between the stomach and the esophagus. They don't have the esophageal muscle strength to overcome and open this barrier by force, which is necessary for vomiting.

Rats need exercise and quality time with their owner outside the cage (at least one hour a day). Make sure the play area is rat proof (most rats like to chew and urine mark). You can buy a play pen or even make one yourself. Your rats should be supervised during play time.


2.5 years

Urine Marking

Rats urine mark. Usually young rats and males urine mark more than older, spayed/neutered rats and females. You might not consider this as your rat’s finest talent but it sure is important for your rat. Urine tells another rat one's species, sex, age, social status, reproductive status, and individual. Rats may also mark because it helps them know where they are and where they've been. Rats are also capable of following the odor trails they have left through the environment.


Female rats go into heat every 4-5 days. She might freeze and arch her back, leap like a frog and vibrate her ears really fast. She might also “hump” other rats (even females).



Since rats are smart, curious, adventurous and love to explore they need a lot of room. Get the largest cage you can afford (aquariums or hamster cages are not suitable!). The best cages out there are “Martins cages” (www.martinscages.com) or “Ferret Nation” by Midwest Cages (there will be a “Critter Nation” coming out late 2008). The Ferret Nation is suitable for larger adult rats only since babies and very small rats could squeeze through the cage bars. Get a powder-coated cage since galvanized cages are more difficult to clean and don’t last as long.

Do a thorough cleaning weekly with a mild soap. If you use bleach, make sure that the cage has been properly rinsed. A quick spot cleaning will be necessary more often (cleaning litter pan, changing blankets, taking out uneaten veggies and fruit etc.).


As for bedding “Carefresh”, “Aspen”, “Cel-sorb plus”, “Yesterday’s News” or “Sunseed fresh world” are good options. You can also use fleece blankets or towels for the bottom pan. You will see what works best for you and the rats (in terms of odor control and/or dustiness). Never use pine or cedar bedding since it is toxic for all small animals! Newspaper is not a good idea because of the ink and lack of odor control. It is recommended to cover up the shelves with fabric shelf liners (fleece, cotton etc.) so the little rat feet won’t have to walk on the bare wire. It’s best to have at least 2 sets so you can wash them more often. You can also use plastic needle point canvas, cut the pieces into the desired size, wrap baby blankets around them and cover the shelves. Whatever you come up with, make sure it’s safe. Wood is a bad idea since the rats will most likely pee on it and will soon stink to high heaven. Urine soaked wood can’t be cleaned and the built-up ammonia is bad for your rats.

Toys and Accessories

Rats need a comfy place where they can sleep or hang out. Spoil your fur -kids with hammocks, plastic or wooden hide-outs. They come in all different sizes and shapes. It can also be as simple as an empty Kleenex box. Rats are intelligent creatures and like to chew (some more, some less). Make sure to provide them with lots of stimulating toys: Apple sticks, empty toilet paper rolls, cardboard boxes, Kleenex boxes, bird/cat toys, ladders, a running wheel (make sure it has a solid surface), PVC pipes, ferret pipes etc. Here are some other fun options: http://www.dapper.com.au/toys.htm or http://www.wonderrodent.com/ratsnest.htm



A rat’s main diet should be good quality “lab blocks” and should be preferred over seed mix. They provide your rat with a balanced nutrition. The problem with seed mixes is that your rat will most likely pick out its favorite bits and leave the rest, which can lead to a dietary imbalance if there are components your rat consistently avoids. Also, seed mixes are usually high in fat. The best brands of lab blocks are Oxbow Regal Rat, Harlan-Teklad or Mazuri.


Provide your rat with small pieces of fruit and veggies. It is fun and stimulating for your rat. Try broccoli (raw or cooked), tomatoes, cauliflower, lettuce (no iceberg), peas, cooked potato, cooked sweet potato, kale, radicchio, parsley, cooked corn (in moderation!), bananas, grapes, berries, apples, mango, kiwi etc. Here is a link to food that you should not feed your rats or very rarely:

http://www.petratscanada.com/ (go to rat care/general care/diet)



Of course rats love treats. As tempting as it is, only feed very small amounts and make sure the treats are low in salt, sugar and fat. Examples: whole-wheat cheerios, whole-wheat cornflakes, puffed rice, puffed wheat, puffed millet, puffed kamut, Gerber (baby) finger food, dry pasta (like spirals or orzo), dry split peas; rolled oats, pumpkin seeds, sunflower seeds and nuts should only be given occasionally since they are high in fat. Other treats that rats like are cooked pasta and cooked rice, cooked chicken and baby oatmeal mixed with soy milk.

Health Care

Weekly Examination

Unfortunately, rats don’t live very long. The average life span is 2 1⁄2 - 3 years. The sad part about owning pet rats is the health issues. Make sure you have a vet who is knowledgeable with rats. Do a weekly examination of your rat. This only takes a few minutes (you can do this while you pet or play with him).

Rats can get quite costly in terms of medical care. Please don’t get rats if you know you won’t be able or willing to treat them. They deserve proper care and treatment like any other pet!

Changes in Behavior

Watch his general behavior: Is he alert or lethargic? You know your rat’s personality and a change in behavior could be an indication of a health problem.


You might see a red substance around your rat’s nose and/or eyes. This substance called “porphyrin” is secreted by the Harderian gland and helps to lubricate the eyes. A little bit of porphyrin is normal, especially after your rat wakes up and your rat will clean it off. However, regular large amounts of porphyrin indicate stress, sickness or poor diet.

Dental Checks

A rat’s teeth should be yellow/orange. If your rat is having a hard time chewing or is losing weight, your rat might have overgrown teeth (his teeth might not be aligned properly – a condition called “Maloclusion” or his teeth are crooked due to a tooth abscess). Since rats’ teeth grow constantly, you will have to trim them regularly if your rat has maloclusion (your vet can show you how).


If your rat is scratching excessively, he could have lice, fleas or mites. You can see fleas and lice but mites only under the microscope. Patches of fur missing and scabs can also be an indication of these parasites.

This problem will not disappear without treatment. Do not let your rat suffer so see your vet as soon as possible. If one of your rats has lice, fleas or mites, the other ones will have it most likely, too. So treat all of them.

Respiratory Disease

The most common health problem in rats is respiratory disease. The primary cause is the bacteria “Mycoplasma pulmonis”. All rats carry it, but not all show symptoms. Infection with mycoplasma makes rats more susceptible to secondary infections. Watch your rat for signs of excessive sneezing, wheezing, labored breathing and/or gasping for air. Ammonia (from urine) can aggravate Mycpoplasma therefore cleaning the cage regularly is a must! Mycoplasma symptoms and secondary infections can be treated with antibiotics.

Since rats have a very delicate respiratory system, don’t smoke around your rat, use strong perfume, incense, pine or cedar shavings, air freshener or harsh chemicals.


Check your rat for lumps. Rats (especially females) can get mammary tumors. They are usually benign and can be removed surgically in most cases. Spaying females may reduce the risk of developing mammary tumors. A lump doesn’t necessarily have to be a tumor. It could also be an abscess or cyst. Abscesses can be drained by your vet.

Pituitary Tumor

Another common tumor is the pituitary tumor. Typical symptoms are loss of coordination, loss of function of arms, legs and mouth, walking in circles, seizures, head tilt (can also be an inner ear infection). Talk to your vet about treatment with anti-inflammatory and an antibiotic (rats do not always respond to the treatment).


Some medications are better tasting than others. In fact, some are downright nasty. If you have to give your rat medicine, try to serve it on a spoon – mixed with food your rat loves like mashed banana, mashed cooked sweet potato, chicken gravy baby food, “Ensure”, soy yogurt, baby oatmeal and soy milk etc. If this method doesn’t work, wrap your little friend into a blanket (just the head sticking out) and feed him the medication with a syringe (without needle of course).


We strongly recommend spaying and neutering all pet rats. Neutering male rats reduces the occurrence of urine marking, odor, and aggression. Spaying of females drastically reduces their risk of developing mammary and pituitary tumors. It is very important to locate a veterinarian who is familiar with rat care, medicine and surgery to perform these procedures.

Getting Ready

Bringing Them Home

When you bring your furry friends home, make sure that the cage, accessories, food and water are ready. Put your rats into the cage and let them explore. You can watch them for a while but then give them several hours (over night) to get used to their new surroundings and smells.

Next day you can continue by opening the cage door and placing your hand by the door and talking to them. Curious as rats are they will most likely come over and check out your hand. Let them explore you and sniff your hand. Later, you can put treats on your hand (like whole-wheat cheerios) and soon they will associate that yummy treats come from your hand. In the beginning, avoid putting your hand inside the cage. The rats might get scared and feel “cornered” and might nip. Remember that rats are predators but also prey! The next step is to interact with them outside the cage (the bathroom or bed is a good place for that). Take a blanket, treats and a hidey house or cardboard box with you.

Depending on the rat’s previous life (some never had human interaction or were neglected and mistreated) it might take him a while to (re)gain trust.

Please be kind and patient! Never punish your rat (scream at him, flick his nose, squeeze, shake or pick him up by the tail)! You would only lose his trust.

It is best to get two or more rats that are already bonded. This way you don’t have to do a quarantine and introduction.

Quarantine and Introduction

If you do get another friend for your current rat(s) you will have to quarantine your new rat(s) for 2 – 3 weeks. This is very important to avoid transmitting possible contagious diseases! The quarantine needs to be in a place with a different airspace. Once you are sure that all rats are healthy, you can start with the introduction. The first step is putting both cages side by side so they can smell and see each other but make sure they can’t reach through the bars. Do that for a few days. The next step is to switch the rats to each other's cage to get used to the other rat(s)’ scent.

Then you can proceed with an introduction on neutral territory (like the bath tub, bed or bathroom) for about 15 minutes per day or so. This might take only a few days or even several weeks. Puffed up fur, fighting (as long there is no blood or bad scratches involved), humping, grooming, pinning down or flipping each other over and squeaking is normal. One rat will usually play the dominant roll. Rats have a hierarchy and have to establish the alpha status.

Once there is no more aggressive behavior towards each other, clean the cage and accessories completely (free from the scent of the rat(s) that lived in it before) and redecorate. Put the rats in and see how they react. Don’t be surprised if there will be some squabbling going on. Watch the rats closely for several days. Usually rats will get along eventually and often become best buddies – play, play fight, groom each other and sleep together however occasionally, there are rats that just don’t get along with a particular rat or just don’t accept any other rats at all. In this case it is OK to house them alone. They would need a lot more human attention though. Don’t assume that a rat that has been kept as a single rat for a while won’t want to have a buddy or won’t get along with other rats. An introduction might just take a little bit longer.

Shopping List


Minimum size 18 x 24 x 30" We really like the Martin's R-695 (available online at www.martinscages.com). Bar spacing of 1/2-3/4" is best, but 1" spacing can be OK for large males. Another great cage is the Ferret Nation Model 140 or 142 (best pricing at www.ferret.com).


If you use a litter-type bedding, CareFresh, Kaytee Soft Sorbent, Sun Seed Naturals, and Aspen shavings are all good choices. Never use pine or cedar shavings--they contain toxic oils that are poisonous to your rat. Some people opt to use all cloth bedding- -fleece, old T-shirts, towels, etc rather than litter, and this can be a good option as well. Most finds that a combination of the two works well. For instance, I put litter in the bottom tray and in a corner litter pan on one of the shelves of the cage, and place cloth bedding on the rest of the cage shelves to soften the wire and provide nesting opportunities.

Litter Pan

A medium sized corner litter pan or two, filled with one of the litters listed above (do not use clay cat litter), can be placed within the cage to encourage your rat to become litter trained. Select a corner that your rat uses frequently, and move any 'accidents' into the pan as they happen.

Hide Box

Your rat will need at least one, preferably 2-3 different nesting enclosures within his cage in order to satisfy his natural need to nest, and to keep him feeling safe and stress- free. Good options include: large plastic igloo, plastic waffle block houses, plastic chinchilla dust baths, custom made cloth 'cubes' , cardboard boxes, large PVC pipe. baskets, wooden houses, and grass huts can be used as well, but must be replaced frequently because they will absorb urine and cannot be cleaned and sanitized properly.

Food Dishes

Medium sized heavy, ceramic crocks, or hard plastic dishes that lock onto the side of the cage (e.g. Lock-Crock) work best to prevent spilling and soiling of food. You will need to have several dishes for feeding both your rat's staple diet (see below), and a variety of fresh foods each day.

Water Bottle

8, 12, or 16 oz glass or plastic water bottle. It is nice to keep an extra on hand so you can exchange for a clean one when it has to be washed and sanitized weekly. Glass works better for rats that are avid chewers.


Rats are intelligent, inquisitive creatures that enjoy chewing and exploring. Provide plenty of rat safe toys, including: hanging wooden bird toys with bell, empty food and tissue boxes, paper towel rolls, untreated wicker baskets, untreated wooden chew toys, small stuffed animals, kitty jingle balls, etc. Be creative, but always keep safety in mind--feel free to contact us if you are not sure if a toy is safe for your rat.

Exercise Wheel

Some rats really enjoy running in an exercise wheel, and others do not. Be sure to choose a solid surface wheel (Wodent Wheel, Silent Spinner, etc) and be sure you purchase the correct size (usually 'large' depending on the brand). Wheels with bars are not recommended due to an increased risk of tail and leg injuries.


As a base/staple diet, we recommend a homemade mixture that incorporates a couple of brands of high quality formulated foods (Mazuri's Rat and Mouse Diet and Oxbow's Regal Rat). Seed mixes should be fed in limited quantities as treats, in order to encourage consumption of all elements (not just favored items like sunflower seeds). More appropriate treats include fresh fruits and veggies, pastas, low sugar cereals, yogurt, lean meat or egg--pretty much anything that is healthy for you (low salt, sugar, and fat), is good in small amounts for your rat. Avoid anything with caffiene, large amounts of peanut butter (choking hazard), most dairy products, alcohol, and carbonated beverages.

Not Recommended

Exercise balls, plastic cages (e.g. Habittrails), aquariums, bedding containing pine or cedar, seed-based diets or treat sticks.


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