''Rattus'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of muroid

rodent Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and Mandible, lower jaws. About 40% of all mammal specie ...

s, all typically called rats. However, the term

rat Rats are various medium-sized, long-tailed rodents. Species of rats are found throughout the order Rodentia, but stereotypical rats are found in the genus ''Rattus''. Other rat genera include '' Neotoma'' (pack rats), '' Bandicota'' (bandicoo ...

can also be applied to rodent species outside of this genus.

Species and description

The best-known ''Rattus''

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

are the

black rat The black rat (''Rattus rattus''), also known as the roof rat, ship rat, or house rat, is a common long-tailed rodent of the stereotypical rat genus ''Rattus'', in the subfamily Murinae. It likely originated in the Indian subcontinent, but is n ...

(''R. rattus'') and the

brown rat The brown rat (''Rattus norvegicus''), also known as the common rat, street rat, sewer rat, wharf rat, Hanover rat, Norway rat and Norwegian rat, is a widespread species of common rat. One of the largest Muroidea, muroids, it is a brown or grey ...

(''R. norvegicus''). The group is generally known as the

Old World The "Old World" () is a term for Afro-Eurasia coined by Europeans after 1493, when they became aware of the existence of the Americas. It is used to contrast the continents of Africa, Europe, and Asia in the Eastern Hemisphere, previously ...

rats or true rats and originated in

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

. Rats are bigger than most Old World

mice A mouse (: mice) is a small rodent. Characteristically, mice are known to have a pointed snout, small rounded ears, a body-length scaly tail, and a high breeding rate. The best known mouse species is the common house mouse (''Mus musculus' ...

, which are their relatives, but seldom weigh over in the wild.

Taxonomy of ''Rattus''

The genus ''Rattus'' is a member of the giant subfamily

Murinae The Old World rats and mice, part of the subfamily Murinae in the family Muridae, comprise at least 519 species. Members of this subfamily are called murines. In terms of species richness, this subfamily is larger than all mammal families excep ...

. Several other murine genera are sometimes considered part of ''Rattus'': ''

Lenothrix The gray tree rat (''Lenothrix canus'') is a species of rodent in the family Muridae. monotypic taxon, only species in the genus ''Lenothrix''. It is found in forests in Indonesia and Malaysia. A common species, the International Union for Conse ...

'', '' Anonymomys'', ''

Sundamys ''Sundamys'' is a genus of rodent in the family Muridae, found mostly in Indonesia and Malaysia.Camacho-Sanchez, M., Jennifer A. Leonard, Yuli Fitriana, Marie-Ka Tilak, and Pierre-Henri Fabre. 2017. "The generic status of Rattus annandalei (Bonho ...

'', ''

Kadarsanomys Sody's tree rat (''Kadarsanomys sodyi'') is a rodent species in the family Muridae that has been recorded only in bamboo forest in Gunung Gede Pangrango National Park, West Java, Indonesia Indonesia, officially the Republic of Indonesia, ...

'', '' Diplothrix'', '' Margaretamys'', '' Lenomys'', ''

Komodomys The Komodo rat (''Komodomys rintjanus'') is a species of rodent in the family Muridae endemic to the surrounding islands of Flores in Indonesia (including Komodo, Lembata, and Pantar), and formerly Flores itself. Its natural habitat is subtrop ...

'', '' Palawanomys'', ''

Bunomys ''Bunomys'' is a genus of rodent from Sulawesi and Buton Island. Currently, eight species are recognised in two species-groups. Species Genus ''Bunomys'' ''chrysocomus''-group: * Yellow-haired hill rat, ''Bunomys chrysocomus'' Hoffmann, 1887 * ...

'', ''

Nesoromys The Ceram rat (''Nesoromys ceramicus''), also known as the Seram Island mountain rat, is a species of rodent in the family Muridae. It is found only in Seram Island, Indonesia, where it has been recorded on Mount Mansuela. It is the only speci ...

'', ''Stenomys'', '' Taeromys'', '' Paruromys'', ''

Abditomys The Luzon broad-toothed rat (''Abditomys latidens'') is a species of rodent in the family Muridae. It is endemic to central and northern Luzon in the Philippines. It is the only member of the genus Genus (; : genera ) is a taxonomic rank a ...

'', '' Tryphomys'', ''

Limnomys ''Limnomys'' is a genus of rodent in the family Muridae endemic to Mindanao, Philippines The Philippines, officially the Republic of the Philippines, is an Archipelagic state, archipelagic country in Southeast Asia. Located in the western ...

'', '' Tarsomys'', ''

Bullimus ''Bullimus'' is an endemic genus of rodent from the Philippines, as first catalogued by Mearns, in 1905. Species Genus ''Bullimus'' * Bagobo rat, ''Bullimus bagobus'', Mindanao * Carleton's forest rat, ''Bullimus carletoni'', Luzon Luzon ...

'', '' Apomys'', '' Millardia'', '' Srilankamys'', ''

Niviventer ''Niviventer'' is a genus of rodent in the family Muridae endemic to Southeast Asia. It contains the following species: * Anderson's white-bellied rat, ''Niviventer andersoni'' * Brahma white-bellied rat, ''Niviventer brahma'' * '' Niviventer b ...

'', '' Maxomys'', '' Leopoldamys'', '' Berylmys'', ''

Mastomys ''Mastomys'' is a genus of rodent in the family Muridae endemic to Africa. It contains eight species: * Angolan multimammate mouse (''M. angolensis'') * Awash multimammate mouse or Awash mastomys (''M. awashensis'') * Southern multimammate mouse ...

'', '' Myomys'', '' Praomys'', ''

Hylomyscus ''Hylomyscus'' is a genus of rodent in the family Muridae endemic to Africa. It contains 21 species divided into six species groups: *''H. aeta'' group **Beaded wood mouse, ''Hylomyscus aeta'' **Mount Oku wood mouse, ''Hylomyscus grandis'' *'' ...

'', '' Heimyscus'', '' Stochomys'', '' Dephomys'' and '' Aethomys''. The genus ''Rattus'' proper contains 64 extant species. A subgeneric breakdown of the species has been proposed, but does not include all species.

Species

Phylogeny

The following phylogeny of selected ''Rattus'' species is from .

Fossil species

In contrast to the large number of living species, as of 2024, just four fossil species have been placed in ''Rattus'' proper: * ''Rattus baoshanensis'' - Late

Pliocene The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

Thailand * ''Rattus pristinus'' - Early Pleistocene China * ''Rattus miyakoensis'' - Late Pleistocene Japan

References

{{Authority control . Rodent genera Taxa named by Gotthelf Fischer von Waldheim Extant Pleistocene first appearances