How to tell the sex of a hamster?

how to tell sex of a hamster

Many moons ago, when I was a child myself, we bought a couple of rabbits from a breeder who assured us we were taking home two males. Low and behold a few months later upon opening their hutch, we found a litter of bunnies. For this reason, it is really important to figure out the sex of your hamster, especially if you have more than one and you don’t want two to become any more.

how to tell if hamster is boy or girl
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Sexing a hamster can be difficult, especially if they are young or have yet to be tamed. But there are key differences between male and female genitalia that are easy to spot and will allow you to determine the sex of your hamster.

Below we will look at the differences between male and female hamsters, their genitalia and ways in which you can tell if your hamster is pregnant.

How to hold a hamster for sexing?

If your hamster is well tamed, then you should be able to cup it gently and rotate them onto their back so that they are belly side up. Holding them in a slightly upright position will allow you to check their genitalia for sex identification.

Alternatively, if your hamster is still young and nervous about being held, then simply place them in a clear container or travel cage. By lifting it high above eye level will give you a view of what lies between their legs.

Differences between male and female hamsters

Most hamsters reach maturity around 6 weeks old, making it easier to spot gender differences. From day one we have been in no doubt whatsoever that our Syrian hamster Oscar is male. He proudly displays his boy bits, quite often sleeps with his legs widely spread and his hind area on show, and grooms himself regularly in this area. This is very common for both Syrian and Chinese hamsters, who testicles are often very prominent.

But, what should you look for if you have a female hamster? One way to identify a female hamster is to find their nipples (of which they have 6 pairs), as male hamsters do not have any. In some breeds of hamsters where their fur is fluffy and thick, this can often prove challenging.

Therefore, the easiest way to sex a hamster is to look at its genitalia and the anogenital distance. A hamster will have two openings (their sexual organ and their anus). For females the gap between the two is hardly noticeable and the area around them will be bald. For males, however, there is a much larger gap and there is likely to be hair. You may also notice their testicles – but don’t be fooled, as male hamsters can retract them if they are feeling cold or anxious.

Other differences between the sexes include:

  • Male hamsters, in general, are larger in appearance than their female counterparts.
  • A female’s behind tends to be more rounded than a male hamster, which in comparison looks elongated.
  • A male hamster has more prominent scent glands which are situated on either side of their flanks or in male dwarf hamsters they are situated near the middle of the belly.

If in any doubt, then you should take your hamster to a vet who can determine the sex for you.

How to tell if your hamster is pregnant?

By 6-8 weeks female hamsters are considered sexually mature. Surprise births are not uncommon with pet hamsters, especially if they have been incorrectly sexed at the pet store and left with male hamsters until rehoming.

It will probably become apparent to you relatively quickly if you have a pregnant hamster, as their girth increases considerably as their appetite surges. Then around 4-5 days before birth, you will notice their abdomen swelling and their nipples becoming dark and enlarged. This is because hamsters can have quite large litters ranging from as few as 4 to as many as 16 pups.

During this time, their behavior is also likely to change as they start preparing for birth. If they share a cage with other hamsters, they are likely to become very territorial and even start fighting with others. They might also start to build a nest, gather food supplies and shy away from human contact.

If you suspect your hamster is pregnant, resist the temptation to clean their cage regularly, handle them less, remove any other hamsters from their habitat and let them have plenty of rest and relaxation.

Depending on the breed of hamster, you should expect a Syrian to give birth within 16 days, Winter Whites in 18-21 days, a Chinese hamster around 18-23 days, with Roborovski hamsters staying pregnant the longest at around 22-30 days in total. Therefore, if you have had your pet hamster for longer than 30 days, yet they are displaying similar symptoms to a pregnant hamster, then you should take them to a vet for a proper health check.


Identifying the sex of your hamster is really important, even if the pet store has already advised you pre-purchase. Determining the gender of a young or baby hamster is really difficult and often they can be mis-sexed.

Hamsters are wriggly animals who don’t like being on their backs, so try to make the process as calm as possible by placing them in a see-through container or travel cage if you are unable to handle them yourself.

It is important to ascertain the sex of your hamster from the get-go, as it will help you to provide the best care possible for them. It could help you seek out signs of pregnancy in any newly owned female hamsters or prevent more babies if you purchase a pair.


We started this website to share our experiences with owning and looking after hamsters. Read our blog for tips and advice to help make your hamster happy.

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