Murinae (Old World rats and mice)

Characteristics and taxonomy

Murines share several anatomical and ecological features: ever-growing incisors, a generally omnivorous dentition, and well-developed hind limbs for rapid movement. Taxonomically they are placed as a subfamily within the larger Muridae, and include many genera such as Mus (mice) and Rattus (rats). Their diversity means form and size vary considerably across species.

• Size and shape: from tiny forest mice to larger commensal rats
• Teeth: specialized incisors with molar patterns useful in classification
• Behavior: solitary to highly social species

Distribution is primarily Old World: most species occur across Africa, Europe, Asia and Australasia, with some introduced elsewhere by humans. Habitats range from tropical forests and grasslands to urban environments and agricultural lands.

Murines exhibit diverse diets (seeds, insects, fruit, human refuse) and reproductive strategies characterized by short gestation and large litters in many species. Their ecological roles include seed dispersion, soil turnover, and serving as prey for diverse predators.

Importance to humans is mixed: a few species (for example, the house mouse and common rat) are model organisms in research and are global commensals, while others can be agricultural pests or disease vectors. As a group they outnumber nearly all other mammal groups except some large families; only the Cricetidae is comparable in species count, and they are more numerous than most mammal orders or many other mammal families. For further overviews of related higher taxa see resources on Muridae and rodent classification (Muridae overview).