All you need to know about hamster cycles, pregnancy and birth

hamster pregnancy and birth

As a family with two girls, the thought of adding a hormonal hamster into the family was a step too far for my husband. Therefore, we decided to get Oscar, our lovely laid-back boy. But do female hamsters experience the same monthly cycles as humans and other mammals and how easy is it for hamsters to mate and breed?

This guide tells you all you need to know about female hamsters including their estrus cycles. We’ll show you how to look after your pregnant hamster and give you top tips on providing the best aftercare for mum and her hamster pups.

Do hamsters have periods?

Female hamsters do not experience monthly periods like we might, although they do produce eggs that require fertilization. Instead they have an estrus cycle in which they release a whitish discharge.

This is repeated every 4 days and the window of opportunity for breeding only happens for 12 hours during the night!

But don’t be fooled, hamsters can multiply rapidly if given the chance. If you don’t want hundreds of hamster babies, we strongly advise separating male and female hamsters from around 5 weeks of age. Once they reach eight weeks old, female hamsters are able to start reproducing and remain fertile for almost the duration of their lives.

A hamsters cycle should not be accompanied by bleeding. If you do notice heavy blood flow during this time, if could be a sign that something is wrong such as a urinary tract infection and you should seek veterinary assistance immediately.

How do you know when your hamster is in heat?

Your hamster will make it clear when she is ready to mate. She will release an overpowering smell to try and attract a prospective partner and may become more agitated when handled, often spreading her legs and flattening her back.

We would not recommend breeding hamsters, but if you do feel it is something you want to pursue then you should do so under the supervision of a trusted, ethical breeder or vet. As most hamsters are solitary, it needs to be handled with the utmost care and sensitivity.

Look out for the white discharge – usually around day 2 of her cycle. For owners who want to breed their hamsters, this is the optimal period for bringing in a male for mating. If, however, she starts secreting a substance that is drier and no longer of the same fluid consistency then she is likely to have gone past the point of breeding.

The best time for your hamster to have babies

If you are still thinking of breeding hamsters, then make sure that your female hamster is of the correct age. It is dangerous to let her mate too young. Most vets recommend hamster owners postpone mating their females until they are at least ten weeks old, as this is when they are considered to be at optimal health.

Remember that it is only on day 2 of her cycle that a female is fertile and can get pregnant. Otherwise, the mating and the fertilization of the eggs will be futile, and your female hamster could cause harm to any potential suitors.

Therefore, timing is key and when you do introduce a male into the mix, do it slowly and under full supervision.

Whilst it is important that no hamsters get harmed in the process, it is not uncommon for the female to act aggressively towards the male. It is her way of testing him to ensure that he is capable of fertilizing her eggs. As with any species, hamsters have the genetic makeup of choosing the right mate for the job and ultimately their survival.

Signs that your hamster is pregnant

If a young female that has spent time with a male hamster in the same cage, then it’s likely the two will have mated. Rather than just guessing if your hamster is pregnant, there are some key symptoms to look out for.

During the first few days, the female will have something named the copulatory plug in the vagina, which is a combination of sperm and the female’s natural mucus. You will recognize it as it is thick in consistency and white color.

The female’s secretions will change, becoming more consistent, unlike the thin one during her regular cycle and persist for longer than normal if a successful pregnancy is underway.

Gestation varies between different hamster species, with Syrian hamsters being the shortest at around 16 days, and dwarf hamsters remaining pregnant for up to 22 days.

Around the 10 day mark, a female hamsters belly starts to swell, and usually becomes pretty noticeable a couple of days before birth.

How to look after a pregnant hamster

Whether it was an intentional pregnancy or not, as soon as you find out that your hamster is having pups, then you must start to provide them with additional care.

Gestating hamsters should have the cage to themselves, as they can be quite aggressive. It will also keep the babies safer once they arrive and avoid any fighting between adults.

Make sure you feed your pregnant hamster plenty of food that is rich in protein and their water is constantly topped up. Also ensure that there is plenty of bedding material, as the female will need it for making a nest for her and her young.

Remove the hamster wheel and any other toys from the cage. This is important in order to prevent your hamster from using up all their energy beforehand and will ensure the safety of the pups once they are born.

How do hamsters give birth?

As pregnant hamsters approach the time to deliver their litter, you will notice that they become restless and have little spurts of activity. You may also notice some vaginal bleeding.

When the moment comes, you will know when the mother to be is in labor as they will be quite vocal, releasing little squeaks from inside their cage. It is important that you do not intervene at all during this process.

The mother is fully capable of giving birth herself although it can take anything between 10 to 30 minutes between pups.

Normal litters contain 6 to 8 pups. The pups are born without any fur and their eyes and ears are closed; however, pups do have their front teeth (incisors) from birth.

Do hamsters kill their babies?

Unfortunately, if you purchased a pregnant hamster from the pet store it is probably too young to be having babies and will therefore not have the best mothering abilities. Because of this, she is more likely to abandon or even cannibalize her babies. If you notice your hamster isn’t attending to the nest or caring for her pups as she should, it is highly likely that they will not survive.

A mother hamsters’ relationship with her children is dictated largely by scent. Therefore, if you enter the cage and touch the babies, you will leave your mark on them. This can confuse the mother and prevent her from recognizing them as her own or she may even feel that they have been tainted. Either way, there is a high probability that she will go on to reject and even kill them.

Another factor that impacts on your hamster’s ability to bond with her pups includes the environment. If your hamster feels stressed by the demands of her litter, she may feel that they are better off gone.

Remember mother hamsters are instinctively compelled to make sacrificial decisions that will benefit the whole litter. Therefore, if there is not enough food, drink or warmth to sustain them all she may choose to reduce numbers to save the stronger pups.

How to look after hamster pups

You shouldn’t need to look after the pups yourself, this is the job of mum. Just bear in mind, however, that for the first few days she will require complete peace and quiet and may act more aggressively towards you if you enter her space. In order to reduce any stressful situations, you should: –

  • Keep the environment as calm and peaceful as possible. Place a blanket over the cage for added security.
  • Minimize interaction for at least two weeks.
  • Spot clean wet areas only and avoid the nest entirely. The cage will not need a full cleanout whilst the pups are young.
  • Place food and drink close the cage door so that you do not disturb them when replacing.
  • Hamster pups rely on their mums until they are weaned at 3 weeks of age.
  • Introduce solid food that is moistened with water when the pups are around 10 days old.
  • Separate male and female pups before 5 weeks of age, to stop mating occurring.

Remember, once your female hamster is no longer pregnant, their bodies begin making eggs again, so they are able to get pregnant quickly afterwards. It is your responsibility to rehome all baby hamsters, and it is important you make sure that they are going to good homes.


Female hamsters don’t have traditional menstrual cycles, but you might notice a whiff emanating from her cage every four days. This estrus cycle will indicate that they are ready to reproduce with a male.

Breeding hamsters is a huge responsibility that requires a lot of knowledge and care. To prevent any unexpected pregnancies, we recommend keeping male and female hamsters apart. If you do want to start breeding hamsters, seek as much advice as possible as you will need to make sure you have the time, money and know-how to look after multiple hamsters at once.


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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