Hamster


Hamsters are rodents belonging to the subfamily Cricetinae. The subfamily contains about 25 species, classified in six or seven genera.
Hamsters are crepuscular. In the wild, they burrow underground in the daylight to avoid being caught by predators. Their diet includes a variety of foods, including dried food, berries, nuts, fresh fruits and vegetables. In the wild they feed primarily on seeds, fruits and greens, and will occasionally eat burrowing insects. They have an elongated pouch on each side of their heads that extend to their shoulders, which they stuff full of food to be stored, brought back to the colony or to be eaten later.

Although the Golden Hamster (Mesocricetus auratus) was first described scientifically in 1839, it was not until 1930 that researchers were able to successfully breed and domesticate hamsters. Pet Golden Hamsters are descended from hamsters first found and captured in Syria by zoologist Israel Aharoni.

Etymology of name
The name hamster derives from the German Hamster, which itself comes from earlier Old High German hamustro. Possibly related to Old Russian choměstrǔ, which is either a blend of the root of Russian khomiak "hamster" and a Baltic word (cf. Lithuanian staras "hamster") or of Persian origin (cf. Av hamaēstar "oppressor")

Hamster behavior can vary depending on their environment, genetics, and interaction with people. Because they are easy to breed in captivity, hamsters are often used as lab animals in more economically developed countries. Hamsters have also become established as popular small house pets.

Characteristics
Two species of hamsters belonging to the genus Phodopus (Phodopus campbelli, Campbell's Dwarf Hamster, and Phodopus sungorus, the Djungarian Hamster) and also two of the species of the genus Cricetulus, (Cricetulus barabensis, the Chinese Striped Hamster, and Cricetulus griseus, the Chinese Dwarf Hamster) have a dark stripe down the head to tail. The species of genus Phodopus are the smallest, with bodies 5.5 to 10.5 centimetres (2.2 to 4.1 in) long; the largest is the European Hamster (Cricetus cricetus), measuring up to 34 centimetres (13.4 in) long, not including a short tail of up to 6 centimetres (2.4 in). The Angora hamster, also known as the long-haired or Teddy Bear hamster, which is a type of the Golden Hamster is the second-largest hamster breed, measuring up to 18 centimetres (7.1 in) long.
Hamsters are stout-bodied, with tails shorter than body length, and have small furry ears, short stocky legs, and wide feet. Their thick, silky fur, which can be long or short, can be black, gray, honey, white, brown, yellow, or red depending on the species, or a mix of any of those colors.

Hamsters have poor eyesight, they are nearsighted and colorblind. However, they have an acute sense of smell and can hear extremely well. Hamsters can use their sense of smell to detect gender, locate food, and detect pheremones. They are also particularly sensitive to high-pitched noises and can hear and communicate in the ultrasonic range.
The tail is sometimes difficult to see; usually it is not very long (about 1/6 the length of their body) with exception of the Chinese dwarf hamster whose tail is the same length as the body. On a long haired hamster it is barely visible. Hamsters are very flexible, and their bones are somewhat fragile. They are extremely susceptible to rapid temperature changes and drafts, as well as extreme heat or cold. Hamsters are hindgut fermenters and must eat their own feces in order to digest their food a second time. This practice is called coprophagy and is necessary for the hamster to obtain the proper nutrients from its food.
Hamsters are omnivorous. They eat most things, and although they should regularly be given a diet of normal hamster food, it is enjoyable for both the owner and the hamster to experiment with other things, such as vegetables, fruits (though these should be removed once they go rotten or bad), seeds, and nuts.
One characteristic of rodents that is highly visible in hamsters is their sharp incisors. They have two pairs in the front of their mouths and these incisors never stop growing and thus must be regularly worn down. Hamsters carry food in their spacious cheek pouches to their underground storage chambers. When full, their cheeks can make their heads double (or even triple) in size. Hamsters in the Middle East have been known to hunt in packs to find insects for food.

Behavior
Golden Hamsters (Mesocricetus auratus) are generally solitary and may fight to the death if put together. Some dwarf hamster species may get along with others of the same species. Siberian hamsters form close, monogamous bonds with their mates. If separated, they may become very depressed. This happens especially in males. Males will become inactive, eat more, and even show some behavioural changes similar to some types of depression in humans. This can even cause obesity in the hamster.
Hamsters are primarily considered crepuscular because they live underground during most of the day, only leaving their burrows about an hour before sundown and then returning when it gets dark. At one point they were considered nocturnal because they are active all night. Some species have been observed to be more nocturnal than others. All hamsters are excellent diggers, constructing burrows with one or more entrances and with galleries that are connected to chambers for nesting, food storage, and other activities.They will also appropriate tunnels made by other mammals; the Djungarian Hamster (Phodopus sungorus), for instance, uses paths and burrows of the pika. Although hamsters do not hibernate per se, they do “close down” a number of systems, such as breathing and heartbeat rate, for short periods of time. These periods of torpor can last up to seven to ten days. Hamsters are known to stockpile large amounts of food where they sleep, making it possible to leave pet hamsters alone for a few days without food.