Arvicolinae Cricetinae Neotominae Sigmodontinae Tylomyinae and see below The Cricetidae are a family of rodents in the large and complex superfamily Muroidea.

The fur of most species is brownish in colour, often with a white underbelly, but many other patterns exist, especially in the cricetine and arvicoline subfamilies.

Like the Old World mice, cricetids are adapted to a wide range of habitats, from the high Arctic to tropical rainforests and hot deserts.

Some are arboreal, with long balancing tails and other adaptations for climbing, while others are semiaquatic, with webbed feet and small external ears.

Although a few exceptions occur, the dental formula for the great majority of cricetids is: Cricetids' populations can increase rapidly in times of plenty, due to a combination of short gestation periods between 15 and 50 days, and large litter sizes relative to many other mammals.