How Many Babies Can a Rat Have?

Having a litter of rats can be a very exciting experience; but very nerve wrecking for the first time ratty grandparent who doesn’t know what size litter to expect. Raising baby rats can be rather taxing on the humans, just as it is with mom. We are responsible for socializing them as they grow, while also feeding them, cleaning up after them, and finding them new homes. The bigger the litter is, the more babies there are to take care of. Can you handle it?

Average Litter Sizes for Pet Rats

Average litters can vary between 10 kits and 15 kits. Huge, right? Rats are all over the board with their litter sizes, unlike dogs and cats. With cats, you can expect 4 to 6 usually. Dogs? 4 to 10. With rats, it’s almost impossible to really give you an idealistic expectation. My best advice for anyone is to assume that you will have 12 (YES, 12!!!) babies to take care of once Momma decides to give birth!

Lowest Likely Litter Sizes

The smallest litters that you are likely to see will be in the neighborhood of 6 to 10. These are relatively small litters. You don’t normally see anything less than six pinkies being born. While this can be a perfectly healthy birth, lower birth numbers tend to be seen in rats who have been poorly taken care of, or simply neglected. They will birth small litters with high mortality rats when they are bred too young, inbred, are sickly, or are malnourished.

Highest Likely Litter Sizes

Generally, a litter of 12 to 16 kittens is NOT unlikely. You are much more likely to have a large litter like this, than a small one! I have noticed a majority of rat litters will hang out between 11 and 14 babies. This is a fairly standard number. You can expect (on the highest end, without it becoming rare) up to 18 babies or so. Hopefully, most litters stay small at around 6 to 10; it is much more manageable for both momma and human! In addition, rats have TWELVE teats. So naturally, you would assume the safe guess would be 12.

World Record for Number of Pet Rat Babies Born

I cannot find a direct, solid record stating how many rats WERE born. Then again, rats are not going to be as likely to hit the record books as a dog or cat would be. I have heard in the past that records seemed to top out at 22; however I kept finding different numbers throughout my research. Some reputable sites also mentioned that it had been said some litters have reached up to 26; unfortunately, there are no true documents to back up this information.

Can Rats Have Just a Single Baby?

Yes, rats absolutely can have a single baby! One of my rats was living proof! She escaped from her cage one night during 2003, and slipped into the boys cage. A few weeks later, she became aggressive towards her female cage mates. Not realizing that she was in fact pregnant (one baby will not show at all, trust me), I separated her and thought nothing else of it. A few hours later, I saw contractions! That gorgeous, pink eyed Himalayan gave birth to an adorable black berkshire boy! Needless to say, he was spoiled rotten! This scenario is EXTREMELY rare, and would be more likely to occur during a quick chance encounter with a male.