Buying Rodents: A Guide

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If you're thinking of buying rats and mice, as with any kind of pet, it's important to take a step back and carefully assess the situation. As much as we all love our rodents, I think we can all agree that their pitfall is their short lifespans. Being smart when buying your rodents to begin with is the best thing you can do to avoid potential health or behavioral problems and increase your chances of having a long-lived pet who will cause you little stress and lots of joy.

If you are new to the rodent fancy, here are a couple of truths.

Not all breeders are good breeders.

Finding a breeder instead of a pet store is a fantastic thing to do, but you have to be careful. Even if a breeder has a pretty website, or even if there are loads of people snatching up exotic types on their facebook page, it doesn't necessarily mean that their animals are going to be healthy or friendly. Further down the page you will find some tips for separating the good from the bad.

Even good breeders can't avoid every problem.

Unfortunately, rodents can come with health or temperament problems that even a good breeder cannot avoid in every case. For example, aggression problems in rats often will not appear until 6-12 months of age even though the rat is fine to begin with. Respiratory problems can also develop later on in life even if their parents were healthy. A good breeder will be completely honest with you. They will tell you about any problems the parents or relatives of your rodents may have had. They will keep their rodents and monitor them for problems, assessing them to make sure only healthy & friendly rodents leave their rodentry. If you have a problem, a good breeder is there to give advice and a replacement or refund if needed. Good breeders will never give you a 100% guarantee of health, and there is no such thing as "myco-free" rodents, so consider those claims a red flags.

Tips for choosing your rodents

Here are a couple of tips when buying your rodents. These can apply whether you're buying rodents from a pet shop, rescue or breeder.

1. Never pick babies that are under 6 weeks of age (rats) or 4 weeks of age (mice).

A big red flag is the case where someone is taking reservations through photos of babies under 6 weeks of age (rats) or 4 weeks of age (mice). Sometimes people may call for reservations when the babies are only 2-3 weeks of age. Under 6 weeks is a crucial development time for rodents, it is very common that an animal may get ill or develop behavioural issues during this time. A good breeder will want to wait as long as possible to assess that they are picking a healthy & friendly animal for themselves let alone to sell. In fact, the longer you wait, the better.

2. Try to make your reservations in person & avoid picking from photos.

The only time you should be picking from photos is if you are purchasing long-distance, or if there's some other reason that you can't be there to choose. No matter how good the photos may look, there is no way to tell what the animal's behaviour is like or whether it has clear breathing. You need to be there in person to health check the rodent. A guide to health checking will appear later in this article.

3. Never be afraid to back out from a purchase. It's your right as a buyer.

If you go to visit the animals, and they aren't quite as healthy or friendly as you were expecting, please don't be afraid to say no. There are plenty more rats in the sea...or on the internet. :-) And there's plenty more demand for rats in the sellers case. Simply tell the seller that they aren't right for you, and that you'll keep looking. This ties in to Tip #2 - if you tell the seller you want to pick in person, it's easier to say no should things be amiss.

4. Ask if you can meet the parents or relatives of the rodents.

This may not be possible if you're purchasing from a pet store or large-scale breeder, but it doesn't hurt to ask. Health check the parents just as you would with the rodents you're choosing. Healthy, friendly parents mean a higher chance of healthy, friendly babies. Ask how old the parents are - the older the better if they are still healthy. A healthy 2 year old male is more impressive than a healthy 3 month old male in most cases, because the male has kept his health for longer. Ask is whether they have had any health problems in the past that they've recovered from; good breeders won't breed from rodents who have been sick full-stop.

Also keep in mind that aggression problems in rats (which are genetic) often don't appear until 6-12 months of age, so bonus points go to the parents if they're older. Aggression isn't only biting humans, it can also refer to how they interact with other rats (they shouldn't fight with eachother; that's aggression). You can ask if the parents have been introduced to new unrelated rats and how they reacted to that situation. This is important to ask because if you decide to get new rats in future, they might not get along.

Keep in mind that male mice, unlike rats, will usually fight and have to live alone.

5. Always health-check your rodents before purchasing, and be realistic.

Remember to remain unbiased. Even if your favourite variety is in the mix, even if the tiny runt has stolen your heart with it's friendliness, remain unbiased. Look at each animal as a whole. How healthy is that friendly runt, are you setting yourself up for heartbreak? Is the prettiest one hiding at the back avoiding attention whilst the others are all investigating & playing with you? Even if it's difficult, try to be realistic. If you do decide to take on a rodent that is "less than perfect" (sometimes they just steal your heart and you can't resist :-)), just remember that you will have to deal with this issue for the duration of the rodents life. Unfortunately even though they are small pets, the vet bills will not reflect their size. The problem may not get better... Sometimes a skittish rodent can turn into a biting rodent. Or sometimes the runt of the litter can turn into the rodent you're at the vet putting to sleep at 6 months of age. OR sometimes they may be absolutely fine. You just need to be aware & prepared for these things.

How to choose a healthy and friendly rodent

Below is a guide to health-checking your rodents.

1. Check their temperament


  • Should be interested in your hands when you open the cage or tub. Bonus points if they're at the door waiting for you.
  • Shouldn't squirm away or squeak when you try to pick them up (except for females on heat in some cases).
  • Shouldn't leap out of your arms when you try to hold them.
  • Should never bite you. Don't mistake play-nipping or nibbling for biting, as these are friendly behaviors, but they should never be painful. Like other animals, rats can control the force they use in their bite. An "accidental" bite for food (or food smelling hands) shouldn't draw blood. A bite that draws blood would be an intended bite.
  • Try putting them on a couch or free range area. They shouldn't be sitting still like stunned mullets. They could be cautious but eventually may start exploring. Bonus points if they immediately start exploring their surroundings - sniffing, chewing, scurrying, etc.
  • Try clapping and watching their reaction (obviously don't clap right in their face). If they scurry away, sit very still, and stay that way for 5 minutes - that's not desirable. If they get over the sound within 10-20 seconds, that's desirable. If they barely even notice the sound, bonus points.
  • Bonus points if they groom you, bonus points if they brux, bonus points if they hand-wrestle with you.


  • Should never bite you.
  • Bonus points if they investigate your hands.
  • Extra bonus points if they climb into your hand.
  • Sometimes mice may scurry away, particularly if they're young. It may be necessary to hold the mouse by grasping the base of it's tail before gently placing it in your hand.
  • When you're holding the mouse, unless it's very young, it shouldn't leap away from you (this is undesirable).
  • When you're holding the mouse, how does it hold itself? If it squishes itself into a small ball, holding it's ears close to its body, this is undesirable. If it stretches out, holding it's ears away from it's body, this is desirable. If it is interested in exploring your hand/arm/shoulders etc, bonus points.

2. Check their breathing.

Respiratory distress is the most common health problem associated with rodents (especially rats). If a rodent is sick, or has a weak immune system, the first sign of illness will be audible breathing. Always hold the rodents nose into your ear and listen carefully. A fantastic healthy rodent will make no sounds, you won't hear anything. Some rats may make a very slight breathing sound (kind of like a person with a blocked nose) which can be permissible but isn't desirable. Some rats may also sneeze, which again can be permissible but isn't desirable. If you hear any kind of rattling, wheezing, or loud foofering sounds, don't buy the rodent full-stop.

Sneezing in mice, or 'clicking' sounds in mice, should also be avoided completely as they tend to turn into something more serious.

3. Check their posture.

Sounds a bit funny, but it's an important one. How is the rodent sitting? Is the rodent hunching itself up with a hump in it's back? Is it holding it's ears into it's body, and not moving around very much? Is their fur raised, standing on end? All of these things are a sign of illness. The rodent should be generally curious, moving around, holding it's ears away from it's body.

4. Check their weight.

Tough to tell for a new rodent owner. When you pick up a healthy rat, it will feel "heavy" for it's size. An unhealthy rodent will have "sunken in" sides and you may see it's spine more easily. Usually an underweight rodent will also have a scraggly coat. Feel the rodents tail from the base to the tip, does it feel bony? Is it thin? These are characteristics of underweight animals. A healthy rodent should have a thick, rounded tail. At the same time, make sure they aren't fat. Fawn (orange) mice usually come along with the obese gene which isn't avoidable for these particular mice, so that's permissible.

5. Check their coat.

A standard coated rat or mouse should have a smooth, shiny and clean coat. It shouldn't appear scraggly or dirty and it shouldn't stand on end. If you're purchasing an older male rat they can sometimes get "buck grease" which looks like yellow/orange flecks on their back, this is caused by their oil glands and is completely normal. Keep in mind that Rex coated rodents can have curly or scraggly fur, so give allowances for that. Patchwork Rats have patchy fur with bald spots, so they can also have allowances.

6. Check their eyes & nose.

Their eyes should appear bright & clean with no irritation. If they have red discharge or any discharge around the eyes or nose, that can be an indicator of illness. If there is discharge around 1 eye, it may just be the case that the rodent scratched it and it may heal. Also note that sometimes rats can have a bit of discharge (even red) around their eye/s if they've been alseep (the same thing as "sleep" for humans) but they usually groom it off after a while.

If you are looking at a Patchwork rat or hairless mouse, pay extra special attention to the eyes as they commonly develop a problem called Entropian. This is a condition where the eyelid curls into the eye, causing extreme irritation. Usually the rodent needs to be put to sleep if they develop the issue. When purchasing Patchworks, always try to have a look at the parents and check their eyes. Patchwork rat parents shouldn't be bred before 6 months of age to check for signs of entropian, so consider it a red flag if the parents are under this age. Eyes should never be squinty (unless they just woke up), never swollen and never should have noticeable hair loss around them. Bright, open, clear, healthy eyes are what you're looking for.

7. Check for lumps & bumps

Run your hand over the rodent and feel for lumps & bumps. Hot spots for tumors are under the front legs or around the chest area.

8. Check for mites.

Mites aren't life threatening but are still important to check for. If the rodent has scabs on it's ears or shoulders, this is an indicator of mites. You can also blow the fur on their back to search for tiny white specks (eggs) or crawlies (little black or red specks). Mites are easily treated with Revolution or Ivomec from a vet. Good breeders usually mite treat their rodents before they leave anyway.

9. Check their gender

Especially with pet stores it's important to check and triple check their gender. Mice can sometimes be difficult to sex and every now and then it's easy to mess up. If you're buying from a pet shop, opt for males, as all too often females from pet shops end up being pregnant. There are plenty of online resources available for sexing rats & mice.

About QRF Registered Breeders

Generally breeders willing to put in the effort and build rapport with us are a good bet, however we don't take responsibility for their rodentries. As a buyer, always use your own discretion when deciding to buy rodents, whether it's from a pet shop, rescue, breeder or even a registered breeder. Hopefully this guide will help you make a good choice in selecting your new pets. :-)