extension of the mouth, extending from the mouth all the way to the rear legs. Food is transferred into these pouches through the diastema. The inside of the pouch contains a large number of folds of dermal papillae. When the pouch is full, it extends and becomes part of the structure of the skin. By 11 days of age, the cheek pouches are fully grown and can carry objects up to the size of a sunflower seed. When the cheek pouches become full, they extend back to the shoulder blades, which restrict movement. Campbell's dwarf hamster is prone to genetic abnormalities in the metabolism of carbohydrates and lipids. They can develop tumours of the mammary glands, lungs, uterus, and ovaries. Tumours can also develop if the animal is exposed to chemical carcinogens. Due to having slow locomotion and an insignificant response to bright lights and humans, as well as having a low population density, field studies allow scientists to study entire populations in the wild. Lifespan Hamsters kept in captivity live for around 2.0–2.5 years. Young hamsters provided widely varied diets early in life are less likely to suffer digestive problems as they mature, but this is not always possible in the wild due to lack of food; this causes the life expectancy of captive hamsters to be greater than that of wild hamsters. Diet As omnivores, Campbell's dwarf hamsters eat a variety of different foods. A balanced diet for a hamster consists of 16-24% protein, 60-65% carbohydrates, and 5–7% fat, with constant access to fresh water. In their natural habitats, dwarf hamsters feed almost exclusively on plant materials. In captivity, Campbell's dwarf hamsters can get the required nutrition from commercially available food designed specifically for hamsters, which typically contain a mix of dry grains, nuts, and seeds that may be fortified with vitamins and minerals. An excess of any one particular seed or nut can lead to digestive problems, obesity, and forms nutritional deficiency. In addition to a commercially prepared seed mix, a balanced diet for a Campbell's dwarf hamster in captivity includes a regulated variety of fresh vegetables and fruits. Dark greens such as kale are rich in vitamins and minerals. Wild vegetables such as yarrow, chickweed, and dandelion and raspberry leaves, are also good sources of protein that help prevent obesity. A hamster in captivity can occasionally eat mealworms or earthworms, which have high protein contents for