Rats have been considered a rapidly multiplying pest for thousands of years. The rodents are found worldwide in all climate zones and areas of life. There are only two native rat species in Germany: the brown rat and the endangered black rat.
In a nutshell
- two native rat species: black rat and brown rat
- differ significantly in appearance and habitat
- Brown rats significantly larger and heavier
- They prefer to live in sewers and near bodies of water
- House rats are found almost exclusively in buildings
brown rat (Rattus norvegicus)
An estimated 95 percent of all rats in Germany belong to this species, also known as the sewer rat. Brown rats have only been native to this country for about 200 years and have now almost completely displaced native rat species such as the black rat due to their rapid reproduction rate and preference for underground habitats. No one knows exactly how many brown rats there are: estimates are based on numbers between one and four rats per human inhabitant.
- up to 350 million rats in Germany
- Carriers of numerous dangerous pathogens
- Rat fleas as the cause of the great historical plague epidemics
- but also transmit cholera, typhus, dysentery, tuberculosis, toxoplasmosis, hepatitis or the dreaded hantavirus
Notice: Because of this, a rat infestation in Germany is notifiable. If you discover rat droppings or even a rat, the regulatory and health office responsible for your community or municipality should be informed.
Occurrence & Habitat
Originally native to Asia, brown rats have now spread almost worldwide through their migration movements. They live mainly in human proximity - here you can find a lot of food - as well as on water. As the original inhabitant of earthworks, brown rats inhabit particularly subterranean, damp cavities such as sewers. It can also be found in cellars and stables, for example.
brown rat
Look
In their appearance, brown rats differ significantly from the rarer house rats. They are significantly larger and heavier, and their ears are smaller.
- Body length: 20 to 28 centimeters
- Tail length: up to approx. 21 centimetres, almost body length
- Coloration: brown-grey to brown-black, tail bare
- Weight: 200 to 400 grams, rarely up to 500 grams
Notice: Brown rats are very rarely seen, as the animals only show themselves around people at night. Incidentally, house rats are almost exclusively found inside houses, since brown rats prefer to stay outside of inhabited dwellings.
way of life
Brown rats live as an extended family in large packs, which can include up to 60 members and claim a specific territory for themselves. The pack members recognize each other by the characteristic family smell, so that strange brown rats are immediately recognized and attacked.
- Females in a pack fertile at the same time
- between six and eight young per litter
- become sexually mature themselves within only three months
- after just three weeks, the offspring are largely independent
- Mother animal ready to receive again
- up to 500 offspring per female and year (including a generation of grandchildren)
Brown rats are mainly active at dusk and at night. They are also excellent at swimming, diving and climbing.
Notice: Rats can slim down surprisingly. Basically, no gap is too small, because where a rat's head fits through, the rest of the body squeezes through without any problems.
lining
Brown rats are omnivores that prefer plant food, but do not spurn carrion and fresh meat or fish. The animals prefer to eat cereals rich in carbohydrates, but also young plant buds and shoots as well as various fruits and nuts. Brown rats are also occasionally predatory and capture bird eggs, young birds, mice or amphibians. They also like to look for food in human waste, which is why feeding ducks in parks is now forbidden. The bread that is fed attracts the grain-loving rats.
feces
Since live rats are rarely seen, you can usually identify a rat infestation by looking at their droppings. Since the animals have no fixed droppings, the legacies can be found almost anywhere. In addition, both the faeces and the urine are used to mark the territory, which is why pooing is not uncommon in exposed places - for example on raised stones.
- fresh droppings: soft, dark shiny
- old feces: grayish, dull, crumbly
- on average about two centimeters long
- rounded ends
- spindle or cone shaped
Notice: Brown rats not only live in the sewers, but also dig burrows with one or more openings themselves. These are often found under embankments or pavement slabs, under dense ground covers and on walls.
Black rat (Rattus rattus)
Like the brown rat, the black rat is a carrier of many diseases dangerous to humans and is therefore considered a pest. However, the population of this native rat species has declined sharply since the brown rat has advanced, so that the black rat is now on the Red List of Threatened Species.
Occurrence & Habitat
The black rat also originally comes from the tropical regions of the world and has spread to almost the whole world, mostly via shipping. That is why this species is also called ship rat. The black rat has been native to Europe for around 2000 years. Unlike brown rats, black rats are primarily found in human dwellings where it is dry and warm. They nest mainly in attics, in cellars and in partition walls. Outdoors, on the other hand, they are less common, which is why you can assume that rats in the garden are brown rats.
rat
Look
In comparison, black rats are much smaller and narrower than brown rats, they also have larger eyes and ears, a more pointed snout and a longer tail. The tail of black rats, which is also naked, is usually longer than the actual body.
- Body length: 17 to 22 centimeters
- Tail length: up to approx. 23 centimetres
- Colouring: brown-grey to dark brown to black
- Weight: up to approx. 250 grams
Notice: House rats differ from brown rats not only in their appearance. The two native rat species also differ in terms of their habitat and diet.
Lifestyle & Feed
House rats are also omnivores, but they rarely eat animal food. The animals mainly eat cereals, fruits and vegetables as well as seeds and nuts. Black rats also live in groups, but their social structure is not as pronounced as that of brown rats. A single female gives birth to between six and twelve young per litter - up to six times a year. If a rat infestation is found, it is often very massive. Like brown rats, black rats are primarily nocturnal and crepuscular. They are also excellent climbers and swimmers.
feces
Since black rats are always on the move, they do not deposit their droppings in a central place. Instead, they spread it over a larger area where they primarily live: in attics, in basements, granaries, stables, sheds, etc.
- fresh droppings: light to medium brown
- old droppings: turns darker
- an average of one to two centimeters long
- resemble curved sausages
- pointed ends
Rat droppings differ from house rat droppings in a number of ways.
Notice: Never touch rat or mouse droppings with your bare hands and wear a mouth and nose protector when removing them. The pathogens are found in the faeces and can be transmitted, for example, through inhalation.
frequently asked Questions
Doesn't the muskrat also belong to the rat species?Native rat species are actually just the two species listed here. From a zoological point of view, the muskrat is not a rat, but a vole, even if a certain resemblance to the brown rat cannot be denied. In contrast to rats, they do not transmit diseases.
What enemies do rats have?Rats are mainly killed by domestic predators such as martens, polecats, owls and owls. Cats also successfully hunt rats, as do some dog breeds (e.g. Jack Russell Terriers). (Used) cat litter, which is laid out on the paths where the rodents run, is considered a tried and tested remedy against a plague of rats. Where there are many cats, rats usually do not appear.
What kind of rat are pet rats descended from?Pet rats, popular pets, are breeding forms of brown rats. In contrast to this, pet rats have different coat colors, are gentler, easy to tame and, most importantly, do not carry dangerous pathogens.