The Best Age To Get A Pet Rat (And Why)

If you’re thinking about getting a pet rat, you might be wondering how old a rat should be before you should buy it? After all, you don’t want to start your rat owning life by accidentally inflicting any kind of cruelty on the rat or its mother do you?

The best age to get a pet rat (and why) is when the rat is about 6 weeks old. The rat should have already been sexed and should not have been kept with the opposite sex since it was about 5 weeks old. This is to ensure that they have been fully weaned and that they are ready to be safely cared for without their mother’s presence.

OK, let’s take a look at the reasons that a rat’s age matters and how to get some idea of the age of your rat if you’re not sure that you’re getting a young rat.

What Is The Best Age To Get A Pet Rat?

We didn’t pick 6 weeks at random out of a hat. Though we’ve heard some people insist that you can adopt rats even earlier, we don’t agree.

Weaning Should Be Done

Firstly, it’s important to note that rats only start to wean at around the age of 4 weeks old. That is until that age – a rat should never be separated from its mother except in an emergency situation because it needs its mother’s milk to survive.

This can be confusing for some rat owners because baby rats are pretty voracious eaters and they can start nibbling at other food sources as young as 2 weeks old. This leads to the conclusion from some owners that it’s OK to separate a rat from its mother at this time.

It’s not.

Healthy Immune Systems Depend On Mother’s Milk

Mother’s milk is essential to the healthy development of rats and, just like in humans, it leads to the rat developing a fully-functioning immune system. If you take the rat away from its mother before it has properly weaned, you are asking for trouble in later life.

A rat has weaned when it no longer seeks out its mother’s milk and only eats solid foods.

Sex Separation At 5 Weeks

Then you need to sexually separate the rats at the age of 5 weeks. That means the boys need their own cage and the girls can stay with their mothers.


Well, rats aren’t people and unlike people, male rats become sexually active at around this age and are happy to mate with their siblings if they’re not kept apart.

The good news is that this is unlikely to result in pregnancy (most female rats can’t get pregnant until they are 6 weeks old) but it’s still quite distasteful and can cause distress to the females.

Further Social Development Is Still Needed

You might be thinking that if you can separate the rats at 5 weeks, why not just sell them at that point? After all, half of the litter won’t be living with their mother by then anyway.

Well, it comes down to allowing the social development of the rat to take place. A 5-week old rat is still a little fragile and when taken to a new home, they can be a little distressed and because they’re still very small at this stage – they can also get lost easily.

In fact, some breeders will insist on holding on to a rat even beyond the 6 weeks stage if they don’t feel that the rat if fully developed by then. We’ve known breeders to hold on to young rats up to 12 weeks before letting them go.

It’s worth noting that young rats of between 6 and 12 weeks will all happily bond with their new owners, you’re not risking being rejected by a rat because you chose to wait for it to develop.

The Easiest Way To Tell The Age Of A Rat

The best place to get a pet rat from is a professional and reputable breeder. They will keep high quality records which explain when the rat was born, it’s breeding lines, etc.  and they will be happy to ensure that the rat you buy is around 6 weeks old.

However, it’s fair to say that not every rat is lucky enough to start out life under a good breeder and there are plenty of “feeder breeders” out there. That is, they breed rats mainly as food for other animals – they’ll be happy to sell you a rat as a pet but they don’t tend to care very much about rats as creatures at all.

They will feed their rats bad food, keep them in cramped conditions and generally neglect their welfare because they feel that as they are only going to be eaten – they don’t matter.

We’d like to see this kind of breeder put out of business, permanently. We’d also recommend that you avoid buying rats from them if at all possible.

Warning signs of these breeders include:

  • Poor or no record keeping
  • Pictures of rats without water or food
  • Pictures of dirty bedding
  • Pictures of rats being kept in aquarium tanks or hamster cages
  • Multiple litters of rats to choose from

If you meet feeder breeder’s rats, they are likely to react oddly as though they’ve never encountered human touch before, they are also far more likely to be sickly and underweight and in poor condition.

If you want to test the waters with a breeder that you suspect of being a feeder breeder, just send them an e-mail (not from your main account) that asks if they can supply a large weekly order for your snakes. If they can, then it’s time to look elsewhere. If not, they may send you a very angry message because most reputable breeders want nothing to do with the feeding scene.

The Two Main Signs Of Age In A Rat

It’s not always easy to tell how old a rat is though the size of a 6-week old rat should mean that it’s obvious that it’s not yet a fully grown adult. However, if it’s not clear then there are two other indicators of age in a rat that are easy to pick up even if you’re not an experienced rat owner: the color of a rat’s teeth and the condition of a rat’s coat.

The Color Of A Rat’s Teeth

After rats are born and their teeth come through, they have very pale yellow incisors. However, as they get older their teeth begin to darken and quite considerably so.

If a rat has reached adulthood it should have a dark yellow or even a slightly orange shade to its teeth.

Once the rat progresses into the final months of its’ life you will find that the teeth become a quite dark orange.

However, it’s worth noting that rat dentistry is not completely foolproof, and some rats might have considerable variation in teeth color.

You should take the color of a rat’s teeth into account when examining other characteristics of the rat’s ageing process too.

The Condition Of A Rat’s Coat

A young rat should have a lovely shiny and quite lustrous coat, it should be silky to the touch and you should see that it’s of an even length all over the rat’s body.

An older rat, which has passed through puberty, will find that its body hair changes (just as it does in humans) and the fur will become longer and you’ll find some “guard hairs” which are thicker and coarser in among the silky hair of youth.

Male rats, particularly, are prone to developing quite a lot of coarse hair following puberty.

There are, however, some exceptions to this rule and rats of a satin nature will tend to keep a shiny, fair coat for much longer than an ordinary furred rat.

One thing that is for certain, though, is that a rat which has dull, lank hair with missing patches, is almost certainly over 18 months old.


What’s the best age to get a pet rat (and why)? 6 weeks is usually the right age to get a pet rat. This gives it time to wean and to properly develop. You should get your rats from a reputable breeder and not a “feeder breeder” and if you’re in any doubt as to the age of a rat, you should check its teeth and its coat.

Darren Black

I'm Darren Black, the owner, and author of 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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