This is the X-Ray of a Winter White called Smirnoff.
She was rescued in October 2020 and had to have immediate special care.
Her cage had to be one level as her legs didn’t move properly.
The vet then explained that her tail was broken, her spine was deformed and she was unable to use her legs properly. She also had infections and a possible tumour.


Physical Differences

The easiest way to tell the difference between male and female hamsters is by the nipples. Females have nipples and males don’t.

When it comes to reproductive parts, there are two ways to tell a male and female hamster apart. The first is that the male will have quite large testicles and their bottom will be longer than the females, this is most obvious in syrians and chinese dwarves. The second and more useful in the smaller species, is the distance between the genital parts. Females have a vaginal opening very close to the anus. In males, the penis is further away from the anus.

Both male and female hamsters have scent glands, although the males’ are often more visible.

Female hamsters will go into heat every 4 days. During this time, they can produce a strong smell. It is important to note that hamsters do not have a period. If there is ever blood coming from your hamsters vagina, it is likely an infection (Pyometra) or tumor which requires a vet visit as soon as possible.

Personality Differences.
There is no scientific evidence to show what type of personality a male or female hamster will have. This guide is based on general stereotypes and the common differences noted by hamsters’ owners. Just like many other animals, every hamster will have it’s own unique personality traits. Some contributing factors may include where the hamster was bred, it’s age, it’s environment and how often it is handled.

Female hamsters are generally more active than males. If you plan on owning a female hamster, especially a Syrian, it is extra important to ensure they have a cage much larger than the minimum requirements for the species. They also need lots of enrichment as they can be erratic and “highly strung” with destructive personalities. Male hamsters tend to have a calmer personality and can be easier to handle. For this reason, males can sometimes be tamed quicker than females and may be a more suitable option for beginners.


Hamsters can hear very well. They have two prominent ears that sit on either side of their head. Because of this, sounds do not arrive in both ears at the same time. These minuscule differences allow the hamster to pinpoint the direction of the sounds. It’s essential a hamster has good hearing, as in the wild it helps them evade any potential predators or other dangers. Hamsters also need to listen to each other when communicating.

Hamsters use their ears in conjunction with other senses such as the whiskers. They feel around with their whiskers, but they can also hear the different sounds made by different substrates which helps them to navigate. As humans, we can hear sounds at frequencies between 16 Hertz and 20,000 Hertz. Sounds that are out of this range are not detected by our ears. Hamsters can hear sounds from 80 Hertz to over 40,000 Hertz. This is far beyond the range of human ears.

Hamsters “talk” among themselves with sounds between 32,000 and 38,000 Hertz. These are sounds we don’t hear. It lets them communicate while not letting predators hear them. The ear shape of the Syrian and Winter White Dwarf hamster are different from that of the 3 other domesticated hamster species. There is a fold in the ear so that they can open and close it.

Syrians and Winter Whites perk their ears up when they want to hear sounds properly. This is often the case when they are curious and stand up on two legs. The ears are then upright and they will be listening out for the sound they heard. When resting, the ears close a little, but are still partly open. In harsh weather conditions in their wild environment, it can be quite cold, and by keeping the ears partly closed, the ear entrance is protected against the cold air. As well as this, the front of a hamster’s ear is covered in a layer of hair so that they are somewhat protected from the elements.

As hamsters have such sensitive hearing, it’s best to keep their enclosure in a quiet place in the house. Too much noise can be very stressful for the hamster, and they will likely stay hidden away in their burrow. Don’t play loud music in the same room as your hamster’s cage. Prolonged exposure to very loud sounds can even damage your hamster’s hearing. Sudden loud sounds can also scare your hamster, so dogs barking or doors slamming can alarm them and make them scared.

A hamster’s hearing is so acute, that they even hear ultrasonic sounds, many of which are emitted from household electronic items such as televisions and laptops. This high pitched noise can be very irritating for a hamster, especially if these items are constantly used around the hamster’s enclosure. It’s best to keep your hamster away from these types of items, or turn them off as much as possible, so the sounds don’t become too stressful for your hamster.

Hamsters can recognise their owner’s voice. Talking to your hamster is a great way to get them to bond with you. Once they get used to you, they are more likely to come out to greet you, in the hope of getting some treats or playtime, as they’ll associate your voice with positive things. It’s best to talk in a low soft voice when your hamster is near. Children should be told not to shout or scream when they play with the hamster.


Hamster Whiskers.
Like many animals that do not see very well or are mainly active at dusk/dawn or at night, hamsters have whiskers. Whiskers are used in navigation and foraging for food. The whiskers are senses that we as humans find difficult to imagine. You can compare the whiskers to the tips of your fingers. When you close your eyes and move your fingers over an object, you feel the material and form an image of what the object looks like. You use your memories to identify it. Hamsters do this with their whiskers. However, whiskers are much more sensitive than fingertips.

A hamster has about 60 whiskers around it’s snout and these whiskers can move independently. They also move independently of the muscles in the head and jaw. Most whiskers are on the sides of the snout, but a few are just above the hamster’s eyes facing upwards. The whiskers on the sides move back and forth between four and twelve times per second. This action is called frisking. This motion allows them to scan their environment. The sense of touch in combination with memories ensures that the hamster knows what it is feeling.

But this isn’t all a hamster’s whiskers feel. They can also observe movements of the air – not only air currents, but also sound waves. It is suspected that by noticing the small vibrations, sounds can be converted into images, similar to a type of sonar. Long whiskers pick up low frequency vibrations and short whiskers detect the higher frequencies. The combination of touch and hearing sound with their whiskers allows hamsters to identify materials. If you place your hand in front of your hamster, it may tickle you with it’s whiskers. This is the hamster’s way of investigating who you are.

Deformed whiskers in Rex and Hairless/ Nude hair varieties.
The Campbell’s dwarf hamster has the Hairless mutation, and the Syrian hamster has both the Rex and Hairless mutations. These varieties of hair cause a change in the shape and length of the whiskers. The whiskers of a Rex hamster are shorter and curled. These whiskers do not function as well, but are still useful in practice. If such a whisker is very short or presses against the body, then incorrect vibrations are measured and eventually no longer interpreted by the hamster.

But if the whisker doesn’t press against the body and isn’t short, then it can pick up vibrations from touch despite being curled. Only the tactile power is limited. Fortunately, naked/hairless Syrian hamsters are not widely bred due to being unethical. Nude/hairless as the name suggests are actually not completely naked/hairless. The hamsters have some short hair on their head and small hairs elsewhere on the body. They also have curved whiskers and eyelashes. The whiskers are very short, but also perceive as normal.

How this effects Hamster Care
Touch is one of the hamster’s most acute senses, so it’s important that we appeal to it as much as possible. This is yet another reason why small plastic pet shop cages are unsuitable. They are colourful and easy to clean which encourages humans to buy them, however, they offer very little enrichment for your hamster. Plastic is not a breathable material and the hard, smooth texture is not interesting for your hamster to
explore.The base tray, house, wheel, tubes are all made of the same texture and so the hamster becomes bored quickly.

Different textures are ideal; whether it’s a digging material, nesting substrate, or other natural item such as cork, wood, slate or hay. The more variety we can pack into our hamsters’ enclosures, the more they can explore different textures. Introducing new items from time to time will help stimulate them and keep them active and happy. Try forage boxes, boredom breakers, cardboard boxes and tubes stuffed with tissue paper and treats etc. Your hamster will enjoy using it’s sense of touch to explore these new things.


Why do some hamsters have red eyes?
Hamsters can have a variety of eye colours from black to brown to shades of red and even pink. Some eye colours are very dark, so they appear black, but on closer inspection a hint of colour may be detected. A hamster’s eye colour is determined
by genetics. Their eye colour is linked to their fur colour. Generally, wild hamsters have black eyes, the other colours are various genetic mutations which have been bred into the species.

The red eyes of a hamster, are not really red! Red eyes are actually transparent! The red colour that we see is the colour of their blood vessels when light is reflected inside the eye.

Are red eyed hamsters blind?
No. Red eyed hamsters are not blind. However their sight is a bit different than hamsters with black eyes. Normally, the black (or other dark colour) of the eyes have pigment which absorbs some of the light entering the eye. Due to red eyes actually being transparent, they do not have any pigment to absorb any of the light, meaning more light scatters in the eye instead of being focused on the best spot for viewing.

Because of this, hamsters with red eyes see less sharply than hamsters with black or darker coloured eyes. Red eyed hamsters also take longer to get used to the dark. Their eyes can take longer to adjust to the lack of light in their environment. Hamsters do not rely very heavily on their sense of sight, and so this slight difference in sight for red eyed hamsters does not impact them negatively in any way, especially as a pet in captivity.

Are red eyed hamsters albino?
No, a hamster with red eyes would be similar to a human with blue eyes. It is simply a genetic mutation and their red eyes are not associated with other characteristics of the albino condition. True albino hamsters do exist, but only in the Campbell’s dwarf species. They not only have red eyes, but are unable to produce pigment over any part of their body, so they will also have white fur and very pale pink skin.

Are red eyed hamsters unethical?
As mentioned previously the cause of red eyes is simply a genetic modification. There is nothing wrong with the hamster and they can live perfectly normal lives. For this reason there is no evidence to say a red eyed hamster is unethical. However, you may be able to spot an unethically bred hybrid dwarf hamster easier, as red eyes do not exist in purebred winter white hamsters. So any “winter white” with red eyes is in fact a hybrid dwarf.

Although red eyed hamsters can be as perfectly healthy and happy as any other hamster, they are unfortunately much more unpopular than their dark eyed relatives. Many people have a negative association with red eyed animals, with some claiming they are “more aggressive” or “evil”. None of this is true. However, it does have a negative impact on red eyed hamsters being adopted, and so, unfortunately, many red eyed hamsters take a long time to find their forever home.


Ethical hamster breeders spend years researching genetics and learning from other experienced breeders. Hamster genetics are extremely complicated, so breeding should be left to the professionals. Education is key, and so it is vital that anyone who wants to start breeding hamsters first studies under an experienced ethical breeder. They must learn how to properly and safely breed healthy, happy hamsters that will improve the species’ overall health, physical condition and temperament.
A thorough knowledge of hamster genetics is essential. We have previously discussed how breeding Winter White and Campbell’s dwarves together creates unethical, unnatural hybrids. Every dwarf hamster sold on Irish resale sites are hybrids, due to ‘backyard breeding’ hamsters from pet shops. Hybrids only exist because of human intervention. Once the hamster’s genetic line has been diluted, even just once, it’s impossible for that line to ever be pure again. This could eventually lead to the extinction of both purebred species.

Hamsters that come from pet stores are often from rodent mills. This means they are bred with whatever other hamster is available. Babies are born three weeks later, and then they’re allowed to breed again, and again. Unethically bred hamsters can have an array of neurological, temperamental and physical health issues. Ethical breeders are constantly striving to produce healthy hamsters with good genetics in order to better the species.


Disclaimer: Hamster Info Ireland does not support or condone the unethical breeding of hamsters. This information is given for the purposes of education and awareness only.

Ethical breeders work hard to better the species and breed for health and temperament first and foremost. They put in huge amounts of work into researching hamster genetics, health and behaviour and work are to improve standards of hamster care and welfare. It takes a lot of dedication, hard work and money, but breeding can be a vert rewarding experience when done correctly. Anyone who is interested in breeding hamsters should be prepared to put in the work, time and costs and work alongside other ethical breeders.

Hamsters from pet shop, backyard breeders or rescues should never be bred under any circumstances. It is vital that the genetic information and lineage of parent hamsters is known before any breeding is carried out. When this is not taken into consideration, hamsters can be born with terrible deformities and it completely goes against everything that ethical breeders stand for.

If you are unsure whether someone is an ethical breeder or a backyard breeder, make sure to ask lots of questions about their hamsters’ lineage. Ethical breeders should have no problem giving you this information and should be able to use the correct terms for the hamster coat colours and types.


Hairless hamsters are genetically bred, it isn’t an illness that can develop. There are people around the world that breed them on purpose. When the care a hamster receives has to change based on their genetics, those genes are deemed unethical to breed as they result in physical handicaps.

Hairless  hamsters have a much shorter lifespan than their furry counterparts. Their bare skin is more sensitive to irritation, this means paper bedding is necessary as wood shavings would be too rough on their skin. They also have a reduced body weight, and are more susceptible to environmental factors, they are less able to regulate body temperature for example. Hairless hamsters are also unable to lactate, so any females that carry a litter to term, are unable to rear them.

Although very rare, the majority of these hamsters can be found in America. An ethical breeder would never try to breed these genes, there is no advantage or reason for a hamster to have no hair.