Hamsters With Big Balls – Why Are Hamster Testicles So Big?

Hamsters are very fragile and prone to several diseases. So we must always watch out for any symptoms. And a common concern appears for general hamster petters about hamsters with big balls.

Why are hamster testicles so big? Well, it is due to their natural growth, and hence there is nothing to worry about. Sexually, hamsters tend to mature quickly and have much bigger testicles.

But there are times when the size of your hamster’s testicle is alarming! Therefore, we are going into a lot of detail about the hamster’s testicle down below.

Hamsters With Big Balls – Why Are Hamster Testicles So Big?

Hamsters are a species of the rodent family. And like every rodent, hamsters have noticeably large testicles. As mentioned above, the testicles of your hamsters grow about ¼ of their body size. So larger hamsters, like the Syrian hamsters, generally have bigger testicles than the rest of their cousins.

Hamsters With Big Balls

They may also seem larger than usual on certain occasions. For example, right after waking up from a nap, or on a hot humid day. 

When Is My Hamster’s Testicle Growth And Size Not A Problem

Here are the reasons why your hamster’s testicle size is not a problem despite having it noticeably very large. 

When Is My Hamster’s Testicle Growth

Growing Hamster Under 3 Months Old

Hamsters normally sexually mature within the first 3 months of their birth. Depending on their breed, some mature a few weeks earlier or later. That is due to their survival mechanism.

A hamster is almost at the very bottom of the food chain in the wild. To survive and not become extinct, they start reproducing very early in their life. Hence, they reproduce a lot since more babies mean more odds for their kind to survive.

And that is precisely why hamsters have such a huge and early growth of their testicles. If your hamster is under 3 months old, noticing a huge growth of their testicle is just natural, nothing to be worried about. 

As your hamster is not only maturing sexually, they are also readily producing a huge load of sperm to reproduce at a huge rate.

Your Hamster Is Sexually Active

Normally, hamsters do a good job of keeping their testicles under their fur. And most of the time, you would not even notice it’s there. But they stop concealing it on certain occasions, one of which is when they are feeling sexually active.

In the animal kingdom, during the mating season, there is a general rule of thumb. That the male will try to seduce his female and fight against other competing males for mating rights.

Your Hamster Is Sexually Active

Different animals use different techniques to seduce females. Peacocks flock their feathers beautifully, lions roar and groan, and hamsters make their testicles visible. 

So hamsters show their testicles to the females as a sign of who is holding more sperm to reproduce and gain the females’ attention.

The Weather Is Changing

Hamsters generally fail to hide their testicles more often in summer, during the hot, humid days. This is generally because the scrotum is designed to protect the sperm. 

During summer, the body heat of the hamsters increases. The sperm in the scrotum would die and the testicle would be harmed if exposed to excessive heat. Hence, the scrotum loosens the muscles to let the testicles hang below the body. Effectively decreasing the temperature of the sperm and the testicles.

During the winter, we may see the opposite effect. The testicles are contracted and are not at all visible. This is due to the decrease in the temperature of the scrotum. So the scrotum contracts the muscles to pull the testicles closer together and close to the body to absorb body heat and get warm.

Your Hamster Just Woke Up From Sleep

As previously mentioned, hamsters like to cover their testicles under their fur. One occasion when it can’t, or rather can be too lazy to cover its testicles, is right after taking a nap. 

Your Hamster Just Woke Up From Sleep

As your little buddy is still dizzy after a good night’s sleep, it might rather forget to cover up its balls. But do not worry; once it regains complete consciousness, it will cover up his testicles well.

When Is My Hamster’s Testicle Showing Signs Of Problems

Having hamsters with large testicles is a natural phenomenon. And there is nothing to be worried about. But when does it start becoming a problem? Well, there are several things to consider.

When Is My Hamster’s Testicle Showing Signs Of Problems

Testicles Would Not Stop Growing Even After The Hamster Matured

As already mentioned previously, hamsters generally take about more or less 3 months to fully mature sexually. The exponential growth of the testicle should stop by then. But if the growth of the testicles does not halt, it might not be a good sign. 

Redness Of The Testicles

If you notice there is redness in the scrotum of your hamster, you should immediately book a meeting with a vet. As hamsters naturally should not have redness in their testicles or their scrotum.

Exponential Decrease In Appetite

A decrease in appetite could indicate a lot of things. But if your hamster has an unnaturally large testicle and is losing his appetite, it might be an indication of a testicular problem.

Swelling Of The Testicles

It might be a bit hard to differentiate the swelling of an already very large testicle. But if you are petting a hamster, you have to take such notice. If your hamster had a very sudden growth of its testicle with redness around it, it is a sign of swelling. And this should be taken into immediate attention.

Here’s a video of what swelling looks like;

Your Hamster Having Lethargy

If you see your hamster with no energy, it is an issue almost always. Hamsters are energetic creatures in the wild. They have soo much energy that it is almost a necessity to buy a hamster wheel. Since if they cannot expend their energy on daily activities, they get depressed.

Therefore, if you notice your hamster with lethargy, it is better to observe for any other symptoms of a disease.

Sometimes urinary infections or bladder tumors cause them too much pain to move around.

Wanting To Drink Too Much Water

Now hamsters drinking excessive water is not always bad. Sometimes they might be too thirsty during a hot, humid day. Or maybe they are still adjusting to their new diet.

But it might also be a sign of a urinary infection or UTI (Urinary Track Infection). If your hamster has any of the above symptoms while taking a huge water intake, it is better to see a vet. Better safe than sorry!

What Type Of Disease Do A Large Testicle Indicate?

Hamsters are very resilient creatures, they have great antibodies to resist diseases. But still, our little friend is not completely immune to diseases and sickness. Hamsters are particularly prone to these illnesses. Here’s a small chart to identify the diseases;

What Type Of Disease Do A Large Testicle Indicate
Testicular InfectionsRedness and Swelling
Testicular TumorsHardened lump around the testicles and scrotum 

Diagnosis, Prevention, And To-Do If Your Hamster Has Bladder Tumor

There are many efforts we can take to ensure that our hamster stays safe, healthy, and happy despite testicular troubles.

Hamster Has Bladder Tumor

Contact A Vet

We can not stress the fact that, if your hamster is in discomfort, the proper way of handling it is to see a vet. 

Conducting A Temperature Test

If you are confused if your hamster has a testicular tumor, you can set up a temperature test.

In this test, place your hamster in a hot humid room before placing him in a cold room. If the testicle expands and does not contract considerably when placed inside the cold room, you must contact a vet. Your hamster most probably has a testicular tumor.

Taking Proper Care Of Your Hamster And His Cage

Testicular issues and irritations can be prevented by placing the hamster cage in a controlled temperature room. Try to keep your hamster cooler in summer, and warmer in winter.

Hamster owners may have concerns about their pet’s health or behavior, and it’s important to be aware of any changes in your furry friend. Two topics you might be interested in learning more about are the best way to give your hamster water and the meaning behind red eyes in hamsters. Our article on can hamsters drink out of bowls? provides helpful tips on how to safely give your hamster water if you’re considering switching from a water bottle. Meanwhile, if you notice that your hamster has red eyes, our article on the meaning behind red eyes in hamsters explains what might be causing this and what you can do about it. Check out our articles for more information on how to keep your hamster healthy and happy.


Here are listed the most frequently asked questions about this topic. Have a look for further information. 

Q: Why do Syrian hamsters have larger testicles than their cousins?

Well, they are the largest hamsters alive, hence they do have much larger testicles than their cousins. It is completely natural, do not worry.

Q: When are my hamsters sexually active?

Hamsters are generally active during the spring and summer seasons.

Q: My hamsters sit on his testicles. Is he harming himself?

No, it is a completely natural phenomenon. They are not hurting themselves, relax!


So we have thoroughly discussed the topic of hamsters with big balls – why are hamster testicles so big? Well, hamsters naturally have immense testicular growth, and it is completely natural and nothing to worry about.

However, do not completely ignore it, and if anything seems suspicious, don’t hesitate to get it checked! The key to keeping your hamster safe and sound is to observe your pet and pay attention to what he is due. Not only will your hamster grow healthy, but it will also be much happier in your household.

Lisa G

Meet Lisa G, the founder and author of RodentsFact.com. With over 3 years of experience studying and observing various species of rodents. Lisa has established herself as a credible expert in the field. Her passion for these often-overlooked animals shines through in her in-depth articles and engaging writing style. Follow her blog to learn fascinating facts and gain a new appreciation for the furry creatures that share our world.

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