Black rat

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Black rat
Black rat (Rattus rattus)

Black rat ( Rattus rattus )

Family : Long-tailed mice (Muridae)
Subfamily : Old World Mice (Murinae)
Tribe : Rattini
Rattus group
Genre : Rats ( rattus )
Type : Black rat
Scientific name
Rattus rattus
( Linnaeus , 1758)

The house rat ( Rattus rattus ), also known as roof rat or ship rat , is a rodent (Rodentia) belonging to the subfamily of the old world mice (Murinae ).


Body shapes of house and brown rats in comparison
Skull ( Museum Wiesbaden Collection )

The house rat has a head-trunk length of 17 to 22 cm, a tail length of 18 to 23 cm, the tail has 200 to 260 rings, the weight is approx. 160 to 210 g.

The snout of the house rat is pointed, eyes and ears are relatively larger than that of the brown rat ( Rattus norvegicus ). The main color forms are completely gray-black (especially with the subspecies rattus ), brown-gray with a gray underside (especially with the roof rat Rattus rattus alexandrinus ) and brown-gray with a white underside (especially with the fruit rat Rattus rattus frugivorus ). In between there are transitions and other color shapes.

The house rat is not the ancestor of the color rat , which is kept and bred as an experimental animal or as a pet . The ancestor of these rats is the brown rat.

Origin and Distribution

The distribution area of ​​the house rat. Ocher colors - the presumed original distribution area

The house rat is also known as the "ship rat" because it was spread around the world by being transported on ships. It originally appeared as a resident of warmer rocky landscapes in the Himalayas , in South and East Asia, adapted to human life as a cultural follower and was brought into the whole world by him.

Especially on smaller Pacific islands with a fragile ecosystem , it not only displaced the native Pacific rat ( Rattus exulans ), but also wiped out numerous native species, especially flightless birds. South India is considered to be her original homeland, from here she came to Persia and Mesopotamia through the Bronze Age trade . From Tell Isan Bahriyat ( Iran ) there is evidence of Rattus rattus from around 1500 BC. BC before. From the Mesopotamia it reached Egypt and the eastern Mediterranean.

The spread on the African and the European continent probably took place in a second wave with the spice trade via ships from the Roman Empire. The oldest evidence of the house rat in Germany comes from Ladenburg near Mannheim , from the 2nd century. During excavations near the city of Haithabu , the occurrence of the black rat was confirmed around 1050, from where it was able to spread further with the ships of the Vikings and later the Hanseatic League .

In Europe the number of house rats is falling sharply. One reason is seen as the fact that the house rat is being displaced more and more by the brown rat , as it is more competitive in today's environment . In Germany the house rat is on the red list of endangered species . Most of the evidence is from Brandenburg, Saxony and Saxony-Anhalt, in other federal states there are mostly only small islands of distribution. It is possible, however, that the species is sometimes overlooked or mistaken for the brown rat. Large populations of the house rat are only found in the Mediterranean countries.

Early reports of plague epidemics caused indirectly by rats, for example the "plague" in Athens described by Thucydides , are used as indirect evidence of the presence of house rats, but the descriptions of the symptoms are not always clear.

The house rat came to Great Britain perhaps with the Romans; there a plague epidemic in Londinium (London) in the 2nd century AD is cited as evidence. The oldest bone finds, however, come from a 4th or 5th century well in Skeldergate, York . Some researchers assume that the rat died out again in the early Middle Ages (poor living conditions due to the end of urban settlements and climate change in the 7th century) and was only reintroduced when the crusaders returned.


Black rat

The house rat is only bound to human settlements in colder regions, where it prefers to live in dry residential and storage buildings (especially on upper floors), but also in cellars and stables. In the wild, she looks for very different hiding spots and builds her nest there. The house rat is both diurnal and nocturnal. As a social animal, it lives in groups that can contain fifty or more individuals. Fixed bills of exchange are marked with urine, which defends territories against other domestic rats. She prefers plant-based foods such as grains, fruits, seeds and roots. She rarely eats animal food such as invertebrates, eggs, mice or fish. As an omnivore , however, if there is a lack of vegetable food, it can switch to animal food sources if necessary.

Reproduction takes place all year round under favorable conditions and the gestation period is 21 to 23 days. Approx. 8 to 15 blind and naked cubs are born per litter, who become independent after six weeks and reach sexual maturity at the age of approx. Four to six months.

House rats are captured by dogs , cats , stone martens , polecats , ermines and owls, for example .

Rat kings have also been found from time to time in the past centuries . These are house rats knotted in a rat heap.

Endangerment status


The house rat is classified in the Red List of Germany (2009) as threatened with extinction due to the sharp decline in populations. It is considered extremely rare.

Endangerment status in the individual federal states:

Status of the red list of house rats in the federal states
state Status RL
BB Brandenburg * safe
BE Berlin * safe
BW Baden-Württemberg D insufficient data
BY Bavaria not rated
HB Bremen 1 Critically Endangered
HE Hessen 0 Extinct or missing
HH Hamburg 1 Critically Endangered
MV Mecklenburg-Western Pomerania * safe
NI Lower Saxony 1 Critically Endangered
NW North Rhine-Westphalia 0 Extinct or missing
RP Rhineland-Palatinate * safe
SH Schleswig-Holstein 1 Critically Endangered
SL Saarland * safe
SN Saxony 2 Endangered
ST Saxony-Anhalt D insufficient data
TH Thuringia 1 Critically Endangered

Harmful effect

The unspecialized, very adaptable wild animals are commonly considered to be food pests .

As a disease carrier

Because the rat flea ( Xenopsylla cheopis ) also parasitizes the house rat as a host , the plague pathogen , the bacterium Yersinia (Pasteurella) pestis , is also spread by and through it. It acquires this significance in relation to the epidemic because the rat flea moves from sick rats to humans and vice versa. Furthermore, free- living house rats can also be used as mechanical vectors for a wide variety of pathogens .

As a pathogen host

Free-living house rats, along with other small rodents, are also reservoir hosts for various types of Borrelia ( bacteria ), which are then supported by vectors such as e.g. B. ticks already occurring in front gardens can be transmitted to animals and humans.


The house rat forms numerous subspecies, some of which are distributed worldwide.

  • Rattus rattus rattus , nominate form of the black rat
  • Fruit rat ( Rattus rattus frugivorus )
  • Alexandrian house rat ( Rattus rattus alexandrinus )
  • Malay house rat ( Rattus rattus diardii )
  • Sawah rat ( Rattus rattus brevicaudatus )
  • Rattus rattus domesticus
  • Rattus rattus albus
  • Rattus rattus ater
  • Rattus rattus brookei
  • Rattus rattus caeruleus
  • Rattus rattus chionagaster
  • Rattus rattus flaviventris
  • Rattus rattus fuliginosus
  • Rattus rattus fulvaster
  • Rattus rattus intermedius
  • Rattus rattus jurassicus
  • Rattus rattus latipes
  • Rattus rattus leucogaster
  • Rattus rattus nemoralis
  • Rattus rattus nericola
  • Rattus rattus picteti
  • Rattus rattus ruthenus
  • Rattus rattus sueirensis
  • Rattus rattus sylvestris
  • Rattus rattus tectorum
  • Rattus rattus varius
  • Rattus rattus nezumi
  • Rattus rattus flavipectus


Web links

Commons : Black rat  - album with pictures, videos and audio files

Individual evidence

  1. ^ House rat - Rattus rattus. In: Accessed July 31, 2019 .
  2. Ken P. Aplin, Hitoshi Suzuki, Alejandro A. Chinen, R. Terry Chesser, José ten Have, Stephen C. Donnellan, Jeremy Austin, Angela Frost, Jean Paul Gonzalez, Vincent Herbreteau, Francois Catzeflis, Julien Soubrier, Yin-Ping Fang, Judith Robins, Elizabeth Matisoo-Smith, Amanda DS Bastos, Ibnu Maryanto, Martua H. Sinaga, Christiane Denys, Ronald A. Van Den Bussche, Chris Conroy, Kevin Rowe, Alan Cooper: Multiple Geographic Origins of Commensalism and Complex Dispersal History of Black Rats. In: PLoS one. Vol. 6, No. 11, e26357, 2011, ISSN  1932-6203 , doi : 10.1371 / journal.pone.0026357 .
  3. a b Meinig, Boye & Hutterer (2009): Red List and Total Species Box of Mammals (Mammalia) in Germany. Federal Agency for Nature Conservation, 70 (1). ISBN 978-3-7843-5033-2 . Pp. 115-153.
  4. a b Red List of Endangered Mammal Species in Lower Saxony and Bremen - 1st version from 1.1.1991 | Nds. State agency for water management, coastal and nature conservation. (PDF) In: Retrieved June 15, 2016 .
  5. Peter Borkenhagen: The mammals of Schleswig-Holstein - Red List . 2014, ISBN 978-3-937937-76-2 .