Hamsters as pets 
The hamster kept as pet least often is the Golden Hamster, also called Syrian Hamster. So-called Teddybear or Black bear hamsters are breeds of blue hamsters. But also four species of smaller hamsters are popular pets, often called dwarf hamsters. These are Roborovski hamster, (Phodopus roborovskii) often called Roborovski, the chinese striped hamster (Cricetulus griseus) and the two subspecies of Phodopus sungorus, the winter white Russian dwarf hamster (Phodopus sungorus sungorus) and Campbell's dwarf hamster (Phodopus sungorus campellii). The care of the dwarf hamsters is similar to that of the golden hamster, but there are differences in feeding and housing needs and temperament. Winter whites and Campell's are fairly popular, in the US the campells more so than the whinter whites, while it's other way round in Europe. Roborovski and Chinese striped Hamsters are somewhat more difficult to breed and keep, they are usually only available from breeders, and therefore limited to serious rodentia fans. Roborovski are especially not suitable for children.
Hamsters are nocturnal by nature, making them less than ideal as pets for people who are normally awake during the day. However, many people prefer them to rats, given rats' unsavory reputation (undeserved as pets). Unlike rats, they are not particularly good at learning tricks but can be entertaining to watch. They are also much smaller than guinea pigs, although equally as furry and appealing, so are more appropriate for homes with limited space.
Hamsters can be kept both in cages and in terrariums, both of which are available in pet stores. Cages are easier to carry, their bars can be used for climbing, and they usually include a convenient front door. On the other hand, glass boxes keep hamsters from throwing litter out of their cages, provide a better view into the hamster's home, and create a quieter and more sheltered interior. In general, terrariums are more appropriate for dwarf hamsters, which are more sensitive to a disquieting environment and which would otherwise need very narrow-grid bars to keep them from slipping through. Middle-sized hamsters, such as the Golden Hamster, especially enjoy climbing the cage walls (the cage should have horizontal and vertical bars) and are more open to the outside world, which is why cages might be the better choice for this kind of hamsters.
Despite the hamster's small size, appropriate housings should always have a floor space of at least 40 cm by 60 cm (16 by 24 inches) and be at least 40 cm (24 inches) in height. Glass boxes must not be higher than their width to allow for a sufficient air circulation. Although smaller in size, dwarf hamsters should have bigger housings than their larger relatives, at least 80 cm by 40 cm (2 feet by 4 feet). The reason for this is that the dwarfs are very active, running and digging a lot, but they often cannot be taken outside their houses for long, because they are not comfortable there and, due to their smaller size, are more endangered when leaving their domicile. Usually hamsters with a bigger and more interesting home will live longer and provide more visual entertainment.
In addition to buying the common housings sold in stores, you can also build customized dwellings. In this case, use only materials that are not dangerous to the animals. Plywood and wood from conifers is not suitable, because hamsters gnaw at their houses and both glue and resin are poisonous for them. Using standard aquarium siciloin to join pieces of solid wood, such as birch or beech wood, creates a safe environment for the hamster, although you must check frequently to ensure that the hamster is not gnawing through the wood. You can also equip a purchased cage with several intermediate levels, connected using stairs. Using wire grid for these platforms instead of solid wood causes serious injuries and is therefore not recommended.
The narrow and smooth plastic toy housings that can be found in some stores are not appropriate as the sole habitat for hamsters. The tight tubes are often densely closed, preventing sufficient air circulation, and the plastic surfaces, while easily cleanable, cannot absorb the hamster's urine like natural materials. The result is a damp and uncomfortable climate that is a perfect habitat for germs and fungi. In addition, synthetic materials are unhealthy when used for gnawing, making plastic tubes, "space stations", and houses an improper and unnatural (though often expensive) permanent home for hamsters. Reserve these habitats for supervised play and activity.
The perfect place for the hamster's home is a well-lit room of constant, moderate temperature (18 to 26°C, 64 to 80°F), in a place without strong solar irradiation that could cause dangerous heating. Especially when wire cages are used, it is also important to avoid air draft. Though they cannot see very far, hamsters become more relaxed and curious when positioned somewhat above the ground (at least 65 cm (2 feet)), from where they can perceive their surroundings.
Cover the inside of the hamster's residence, including all intermediate levels, with a sufficiently thick layer of wooden litter for rodents, available in pet stores. Although alternative materials may work as well, most of these bear additional threats, NEVER use pine or cedar as it causes respitory infections. Cat litter is dangerous, because gnawing and eating the chunks is deadly.
Hamsters are nest builders and a steady supply of fresh strips of tissue or newspaper (with soy-based ink only) allows them to build a secure and comfortable spot in a corner of their enclosure or in their hiding house. Hay, from shops or even fresh from the garden, is also a valuable building material for cosy hamster nests, which, as an additional bonus, is also perfectly edible.
A sand bath can provide a hamster with entertainment and helps them groom. In the desert (their natural habitat), hamsters will roll around in the sand, which cleans their coat and prevents it from getting too oily. Dwarf hamsters in particularly enjoy this activity. Be sure to use a dish that will not tip over. Heavy ceramic and metal dishes are preferred. You can fill the dish with fine sand (pumice or chinchilla sand is best), but DO NOT use any sort of 'dust' bath AT ALL. This can cause respiratory and eye problems.
Regular cleaning of a hamster's home is crucial for the hamster's health. The home must be cleaned at least once a week by replacing the soiled bedding where necessary. Hamsters are fairly neat in their bathroom habits; if their enclosure is regularly cleaned, they choose one small location in which to urinate and defecate, making the cleaning simple. They may have many (usually hidden) places used as toilets.
Another important component of a hamster's home is a hiding place where the animal can rest during the day. Not all commercially available houses are adequate. The houses should be of sufficient size and be closed on at least two sides. The same building materials are appropriate for these as for the larger cages, although even a small cardboard box will work (and which will have to be regularly replaced and NO INK!!!!). Some houses add features such as a removable roof that helps to take away collected food (especially perishable items).
Hamsters are solitary animals and prefer to be alone most of the time. While sometimes two or more animals can live peacefully within one home, there can be bloody fights. In their natural habitat, there is substantially more empty space so that each hamster can have its own large territory. If more than one hamster is to live in a cage, then the cage must be larger (at least 40cm x 40cm per hamster) and there must be separate hiding houses for each animal. In any case, even after a long period of peaceful coexistence or even mating, there can be violent biting. In this situation, the hamsters should be separated immediately. Note also that, if a male and female hamster live together without fighting, then they will usually reproduce rapidly, thereby causing more space problems.
Despite their cuddly appearance, hamsters have long, thin, sharp teeth that can pierce a finger that is mistaken for a carrot or for a predator. When they are accustomed to being handled and are not startled, however, they are not inclined to bite and can be placed in the custody of responsible school-age children. Like many rodents, their teeth grow continuously and they must have appropriate things to chew on to relieve their instinctive gnawing and to help keep the teeth at a healthy length. They will gnaw on whatever is available, so they must be kept in enclosures that they cannot chew through. When the hamster is kept in or near a bedroom, their nocturnal nature combined with their gnawing habit can become distracting.
Exercise and entertainment 
Like all pets, hamsters need exercise and entertainment to maintain their physical and mental health. An exercise wheel allows hamsters to run full speed to their hearts' content, but is not as mentally stimulating as more elaborate enclosures including additional toys such as plastic or wooden tubes that somewhat mimic the burrows that they might have in the wild and allow their owners to enjoy their activities. Most commercial exercise wheels marketed for hamsters have rungs which are not suitable for hamsters due to the fact that a hamster could get injured in one.
Clear plastic hamster balls or cars are available, into which the hamster is placed and then, by its own action, explores an entire house or yard. Use these toys only under supervision and use common sense. Unsupervised hamsters in these toys can become trapped against furniture and panic or they can roll down stairs, injuring themselves. Do not leave them in these toys for extended periods, especially on warm days, and make sure to remove them frequently and allow them access to water or fresh fruits or vegetables. Toys should always invite the hamster to explore and use them at its own will, without forcing or violence.
If they are handled frequently, hamsters enjoy being out of their enclosures and having the opportunity to explore. However, they must be kept away from holes in the wall or in large pieces of furniture, because they will seek out the dark and burrow-like confines of those areas and it can be difficult or impossible to convince them to come out again.
Pet stores can provide basic food for hamsters that provides their non-nutritional needs, but they also like fresh vegetables and fruits, dog food, and even killed insects, which make up an important part of their natural diet. However, not any nutrition is suitable for hamsters and some food, such as sweets made for humans or poisonous plants like the leaves of the tomato, may be most dangerous for the hamster's health. Like with most other animals (and humans), it is not true that hamsters can decide which food is good for them and they will usually eat anything that is offered.
Hamsters should also always have fresh water available. Appropriate drinking devices can be found in stores. Being small animals that are adapted to the life in arid environments, hamsters can also ingest all necessary liquid via sufficient amounts of watery vegetables, such as cucumber, without any negative effects. However, providing water is usually more convenient and can be an easy way to add medication or vitamins to the hamsters diet. Both water and vegetables must be fresh and have to be exchanged frequently, usually once a day. Water must not be given in open jars, since it is likely to be polluted and because wetness is generally very unhealthy for hamsters (that clean themselves very carefully without the need of additional water).
In detail, the solid food components can be divided into three categories: dry, fresh, and animal food. Dry food makes up the bulk of a hamster's diet. Besides the standard rodent food sold in pet stores, most other kinds of seeds, kernels, and nuts can be given. Care should be taken to limit the amount of fat contained within the diet. Especially sunflower seeds, nuts, almonds, and sesame are most nutritive and are to be considered as a treat rather than as basic food. All kinds of grain, rice, noodles (dry), dry pea] and lentils on the other hand can be provided less restrictively: about 120 g for a medium hamster and, depending on size, about half the amount for a dwarf hamster is sufficient. Bread and similar bakery products contain many ingredients (e.g. yeast) that can trouble the hamster's digestion system. They should be given in small amounts for gnawing or be replaced by special wafers as found in pet stores. All dry food should be appropriate in size. Especially small hamsters often cannot cope well with large seeds, even if they are sold under the label "hamster food". Bird food like millet is a noteworthy alternative for small hamsters.
Hay, although also belonging to the dry food category, can be provided in large amounts at any time. It does not contain notable amounts of fat, still is liked by most hamsters, supports the hamster's digestion system, serves as a hiding place, and is often used for nest building. In addition it is cheap and can even be produced in your own garden easily.
Fresh food is also an important part of the hamster's diet. As mentioned above, cucumber is a good supplement of water. Fresh grass, carrot, all kinds of lettuce, leaves and even branches' of (non-poisonous) plants are also no problem in general. However, no conifer wood must be fed since resin is poisonous for hamsters. In smaller amounts, grown hamsters also appreciate apple, pear, sweet paprika, tomato (only red parts), banana, mango, strawberry, and even small pieces of orange. Too much sweet fruits on the other hand are not healthy. All kinds of cabbage should be avoided, since they may cause flatulence, which is quite dangerous for the hamster's sensitive digestion system.
Very young hamsters (6-8 Weeks) should eat only carrots and small grains. Even water can damage their digestion system and be a deadly danger. Ill hamsters are also preferably provided with a more conservative diet. If accepted, herbs can also help to strengthen the hamster's health, though they cannot replace a veterinarian in case of a disease. Daisies (the flowers, not the stems or leaves) and dandelions are likewise appreciated. Plants used for hamster foods should never be placed near open windows because hamsters are more sensitive to chemical pollutions, due to their small body weight.
Finally animal food is a major component of some hamsters' natural food. As pets, a large part of this can be replaced by dry food. Still, hamsters need some animal proteins for their health. While some people like to provide living insects from pet stores to their hamsters, others will prefer to give them dry dog biscuits. Some hamsters are known to accept yoghurt (natural, without sweet ingredients) or soft cheese (low fat, not too salty), and in any case egg noodles are usually taken gratefully. If (dry or soft) dog or cat food is given, then the fat content has to be checked carefully. Furthermore, it must not contain molasses, which would harm the hamster.
In addition, a special salt stone (available in pet stores) belongs in every hamster cage. Although this huge amount of mineral salt is hardly used up by generations of hamsters, it is necessary for their life. Vitamin additives for rodents are not required and usually fresh vegetables are to be preferred. If the hamster is diseased or ill-nourished, vitamins or medications may be needed.
It might be noted that many hamsters tend to carry away food from their food source (by carrying it in their cheek pouches) and hoard it away in a cache hidden somewhere inside their container. These caches, when combined with hamster urine or a leaky water source and poor airflow, can grow mould or start to rot, creating a hazardous environment for the hamster. To keep this from happening, clean hamster cages frequently. It is because of this behavior that hamsters got their name. The German word for hoard is "hamstern."
There are also many foods that a hamster should never eat. This includes all kinds of human sweets, such as chocolate or candy, which are unhealthy and even dangerous. Furthermore, poisonous plants (also check indoor plants if the hamster is taken outside its housing) constitute a considerable danger. Other than this, mainly the various unhealthy and chemically treated products usually consumed by humans can cause problems.
Campbells dwarf hamsters are especially sensitive to Diabetes mellitus, and other dwarf hamster species may be somewhat sensitive too. Diabetes mellitus in hamsters is often caused by intake of simple sugar. Therefore it is essential to avoid hamster food and snacks containing molasses, honey, sugar, fruit sugar or other sweet stuff. Intake of sweet fruit should be limited to small snacks. Even with golden hamsters it may be useful to follow these guideline in order to avoid overweight and digestion disturbances.
Bedding is an important part of a hamster's environment. They sleep in it, walk on it, play in it, burrow in it, bury in it and use it as a litter. Therefore, it is important to provide a safe, comfortable form of bedding for any hamster. There are several options available when it comes to bedding. In the past, pine shavings and cedar shavings were a popular form of bedding until it was determined that the phenols found in pine and cedar shavings can cause serious respiratory problems in hamsters. Therefore, pine and cedar bedding should never be used even though it continues to be sold. Aspen shavings are a safe alternative to pine and cedar bedding. Other safe bedding alternatives include corn cob bedding, bedding made of recycled wood pulp (such as the brand Carefresh), newspaper pellets (such as the brand Yesterday's News), as well as others.
Reproduction and longevity 
Hamsters typically live no more than two to four years in captivity, less than that in the wild. Because of their short life expectancy, hamsters mature quickly and can begin reproducing at a young age (two months). Left to their own devices, hamsters will produce several litters a year with several babies in each litter. Male and female hamsters are therefore usually kept in separate enclosures to prevent the addition of unwanted offspring. Extreme care should be taken when breeding hamsters because if the female is not in heat there is the possibility of her being violent towards the male - with possibly fatal consequences.
Also, remember that if the room temperature gets low enough (below about 65°F / 18°c) the hamster will go into hibernation. This can be very dangerous to your hamsters health, as once a hamster goes into hibernation its body may not be strong enough to properly wake up again. Please, don't assume that your pet is dead because it stops moving. It may just be hibernating. To get a hamster to go out of hibernation it needs to be moved into a warmer location and allowed to slowly return to temperature. Do not shock or startle a hamster in this situation.