Hamsters are a group of rodents that constitute the subfamily Cricetinae within Cricetidae, a family that also includes voles, lemmings, and muskrats. They are expert diggers and use their powerful forelimbs and hindlimbs, along with their snouts, to construct burrows underground. These burrows have one or more entrances, with specialized chambers for food storage. In fact, these rodents are characterized by well-developed cheek pouches, which they use to carry food to their burrows and eventually store it in the chambers.
There are 19 species of hamsters, of which many are kept as pets. The most commonly domesticated hamsters include the Syrian hamster, the Roborovski hamster, and the dwarf hamsters.
In the wild, hamsters are crepuscular, meaning they are most active during twilight hours, whereas pet hamsters are typically nocturnal.
The largest species, the European hamster, grows 8 to 14 in (20 to 35 cm) long, with a tail length of 1.6 to 2.4 in (4 to 6 cm). In contrast, the smallest species, the Roborovski hamster, has a body length of 2.5 in (6.3 cm) and a tail length of 0.125 in (0.3 cm).
While the European hamster weighs 7.8 to 16.2 oz (220 to 460 g), the Roborovski hamster weighs only about 0.56 oz (16 g).
They have a stout body with short, stocky legs, all covered in thick, silky fur. This coat varies in color by species, ranging from black and gray to honey and white. Most species also have a tail, about one-sixth of their body length, except for the Chinese hamster, whose tail is almost equal to its body length.
They have a unique two-chambered stomach (forestomach and glandular stomach), which helps them digest both plant and animal matter effectively.
The name ‘hamster’ comes from the Middle High German hamastra. In fact, it inspired the German verb hamstern, which literally means ‘to hoard’, a reference to the habit of stockpiling food.
All species of hamsters are classified into 9 genera.
Hamsters are native to a specific belt of the Palearctic region, stretching from Central and Eastern Europe through the Middle East to Central and East Asia.1 Such specificity of their range stems from their preference for arid to semi-arid habitats, such as steppes, grasslands, and meadows, which provide moderate temperatures suited to their physiology and predictable food sources. However, as domesticated pets, hamsters now have a nearly cosmopolitan distribution worldwide.
These rodents are opportunistic omnivores, feeding on both plant and animal matter in the wild as available. Most of their diet consists of a mixture of seeds, grains, green shoots, roots, and leaves. However, to meet their protein requirements, they supplement these plant sources with insects, such as ants, crickets, and beetles, as well as other invertebrates, including snails and slugs.
When kept as pets, hamsters are typically fed a balanced blend of seeds, grains, and nuts, supplemented with fresh fruits, vegetables, and protein sources like dried mealworms.
Since their vision is poor, hamsters rely on their whiskers to navigate their surroundings. Once they have gathered food, they avoid eating in the open to stay safe from predators. Instead, they quickly load their cheek pouches and rush to the safety of their burrows. Within these burrows, they hoard the food in specialized chambers, creating a stockpile to sustain them through the winter.
Some species, such as the European hamster, typically hibernate for about 4 to 6 months, from late autumn to early spring. To sustain extreme winter conditions, their metabolism reduces greatly, along with a fall in body temperature to match the ambient burrow temperature.2
Hamsters that are usually kept as pets do not hibernate. Instead, when ambient temperatures drop below 18 to 20°C (64 to 68°F) for prolonged periods, they may enter torpor, a phase during which they show extremely reduced activity and are often mistaken for dead.3
Hamsters typically survive 1.5 to 2 years in the wild, though they may live longer in captivity. For example, the European hamster has been recorded to have a maximum lifespan of 3.6 years in captivity.4
According to Guinness World Records, the oldest hamster ever recorded (as of January 2001) was probably a Syrian hamster from the United Kingdom that survived 4.5 years.
In the wild, most hamsters are solitary and territorial, coming together briefly during the breeding season. The females remain sexually active for only about 18 months, entering estrus every 4 days, during which the males mate with them.
Depending on the species, the females then undergo a gestation period of 16 to 23 days, after which they give birth to their young. While dwarf species, such as Roborovski hamsters, have a litter size of 4 to 6, Syrian hamsters may bear a maximum of 24 newborns per litter. These newborns are hairless, blind, and fully dependent on their mother. In most species, the newborns develop fine fur within 3 to 5 days. They start crawling in a week, and by 3 weeks, they are weaned and become independent.
Interesting Fact:
Female hamsters may cannibalize their own litter if they feel threatened, stressed, or if the litter size is too large.5
Eventually, the young attain sexual maturity, though the timing varies with species. While Syrian hamsters reach sexual maturity at 4 to 6 weeks, Chinese hamsters reach sexual maturity at 2 to 3 months.
Their common predators include birds of prey, such as red kites, black kites, common buzzards, eagle owls, and lesser spotted eagles. They are also preyed upon by mammals, such as foxes, weasels, badgers, and stoats. Additionally, hamsters living close to human habitation also fall prey to domesticated cats and dogs. Moreover, some reptiles, such as steppe rat snakes, slither into hamster burrows and hunt them.