Black rat (Rattus norvegicus)

Brown rat (Rattus rattus)

Rattus rattus

I think I may have a rat problem?

House mice are small, usually between seven to nine centimetres long and are grey in colour. House mice are mainly active at night, although you might see them during the day. Nests are made of shredded fibrous materials such as paper and look like a ball of material loosely woven together, usually about 12 to 15 inches across.

You may find partially nibbled food and small droppings.

Rats are larger in size (32cm to 43cm from nose to tail) and are of a greyish brown colour with a long hairless tail. Droppings near food sources are the most common sign of rats along with evidence of gnawing, rub marks, tracks, burrows and nests.

Mice and rats contaminate the environments in which they live through their urine, droppings and hairs. They can carry a wide range of diseases which can be passed on to humans, either by directly contaminating food with droppings and urine, or by contaminating surfaces. Rats in particular can pass on the potentially fatal Weils Disease, carried by around 15 to 30 per cent of the rat population.

They can also cause extensive structural damage to property. They are capable of gnawing a range of materials. There is a significant risk of fire and electrocution as a result of mice and rodents chewing through electric cables and wiring in particular.

Reduce the risk of mice and rats in your home Mice and rats may be discouraged and infestations prevented by improving hygiene and by blocking access points to your home:

  • check that air bricks are in place and intact (do not block them)
  • Inspect for access points around gas, electricity and water pipes
  • Check that doors fit tightly
  • Fit cone guards around the bottom of drainpipes to prevent rats from climbing up
  • Fit metal balloon guards to the bottom of drainpipes to prevent them climbing up the inside

Improved hygiene will restrict the availability of food for mice and rats, reducing the chances that they will remain and breed successfully. Examples of how hygiene can be improved are:

  • store food carefully so that they do not have access to food sources
  • sweep up any spills as soon as they happen
  • remove rubbish and other materials that can be used by mice
  • clean up under work units and other areas where food debris can build up

Controlling mice

House mouse problems will sometimes occur despite hygiene and proofing action. In such circumstances, it will be necessary to take control measures in order to eliminate the infestation. There are two methods of control available:

  • trapping
  • poison baiting

If you have a mouse problem that you do not wish to deal with yourself, contact the environmental health department of your local council or call in a pest control company.

Before attempting to deal with a rat problem yourself it is essential to carry out a survey to identify where rats are living, feeding and drinking, and the routes they take between these areas. Look for:

  • holes and burrows
  • runs and tracks
  • droppings
  • footprints
  • other signs such as sightings or a musky smell

Find out how the rats are getting into your home (this can be done by blocking any holes with newspaper (or similar) and coming back 24 hours later to see which holes have been re-opened). You can then take preventative action to permanently block the access holes.

If you have a rat problem that you do not wish to deal with yourself, contact the environmental health department of your local council or call in a pest control company.

The leaflet from Defra called 'Rural Development Service Technical Advice Note Rats' gives advice on different methods you can use to get rid of rats.

Rats are various medium-sized, long-tailed rodents of the superfamily Muroidea. "True rats" are members of the genus Rattus Rattus, the most important of which to humans are the black rat, Rattus Rattus, and the brown rat, Rattus Norvegicus. Many members of other rodent genera and families are also referred to as rats, and share many characteristics with true rats.

Rats are typically distinguished from mice by their size; rats are generally large muroid rodents, while mice are generally small muroid rodents. The muroid family is very large and complex, and the common terms rat and mouse are not taxonomically specific. Generally, when someone discovers a large muroid, its common name includes the term rat, while if it is small, the name includes the term mouse. Scientifically, the terms are not confined to members of the Rattus Rattus and Mus genera, for example, the pack rat and cotton mouse.

Species and description

The best-known rat species are the Black Rat (Rattus Rattus) and the Brown Rat (Rattus Norvegicus). The group is generally known as the Old World rats or true rats, and originated in Asia. Rats are bigger than most Old World mice, which are their relatives, but seldom weigh over 500 grams (1.1 pounds) in the wild.

The term "rat" is also used in the names of other small mammals which are not true rats. Examples include the North American pack rats, a number of species loosely called kangaroo rats, and others. Rats such as the Bandicoot rat (Bandicota  Bengalensis) are murine rodents related to true rats, but are not members of the genus Rattus. Male rats are called bucks, unmated females are called does, pregnant or parent females are called dams, and infants are called kittens or pups. A group of rats is either referred to as a pack or a mischief.

The common species are opportunistic survivors and often live with and near humans, therefore they are known as commensals. They may cause substantial food losses, especially in developing countries. However, the widely distributed and problematic commensal species of rats are a minority in this diverse genus. Many species of rats are island endemics and some have become endangered due to habitat loss or competition with the Brown, Black or Polynesian rat.

Wild rodents, including rats, can carry many different zoonotic pathogens, such as Leptospira, Toxoplasma Gondii, and Campylobacter. The Black Death is traditionally believed to have been caused by the micro-organism Yersinia pestis, carried by the Tropical Rat Flea (Xenopsylla Cheopis) which preyed on Black Rats living in European cities during the epidemic outbreaks of the Middle Ages; these rats were used as transport hosts. Other zoonotic diseases linked to pest rodents include Classical swine fever and Foot-and-mouth disease.

The average lifespan of any given rat depends on which species is being discussed, but many only live about a year due to predation.

A domesticated rat Specially bred rats have been kept as pets at least since the late 19th century. Pet rats are typically variants of the species Brown rat, but Black rats and Giant pouched rats are also known to be kept. Pet rats behave differently than their wild counterparts depending on how many generations they have been kept as pets. Pet rats do not pose any more of a health risk than pets such as cats or dogs. Tamed rats are generally friendly and can be taught to perform selected behaviours.

As subjects of scientific research Main article: Laboratory rat A laboratory rat strain known as a Zucker rat. These rats are bred to be genetically prone to diabetes, the same metabolic disorder found among humans. In 1895, Clark University in Worcester, Massachusetts (United States) established a population of domestic white brown rats to study the effects of diet and for other physiological studies. Over the years, rats have been used in many experimental studies, which have added to our understanding of genetics, diseases, the effects of drugs, and other topics that have provided a great benefit for the health and wellbeing of humankind. Laboratory rats have also proved valuable in psychological studies of learning and other mental processes (Barnett, 2002), as well as to understand group behaviour and overcrowding (with the work of John B. Calhoun on behavioural sink). A 2007 study found rats to possess metacognition, a mental ability previously only documented in humans and some primates.

Domestic rats differ from wild rats in many ways. They are calmer and less likely to bite; they can tolerate greater crowding; they breed earlier and produce more offspring; and their brains, livers, kidneys, adrenal glands, and hearts are smaller (Barnett 2002).

Brown rats are often used as model organisms for scientific research. Since the publication of the Rat Genome Sequence, and other advances such as the creation of a rat SNP chip, and the production of knockout rats, the laboratory rat has become a useful genetic tool, although not as popular as mice. When it comes to conducting tests related to intelligence, learning, and drug abuse, rats are a popular choice due to their high intelligence, ingenuity, aggressiveness, and adaptability. Their psychology, in many ways, seems to be similar to humans. Entirely new breeds or "lines" of brown rats like the Wistar rat have been bred for use in laboratories. Much of the genome of Rattus Norvegicus has been sequenced.


As food

Rat meat dishes in Yangshuo, Guangxi, China Rat meat is a food that while taboo or even forbidden in some cultures, is a dietary staple in others. Taboos include fears of disease or religious prohibition, but in many places rats are so plentiful compared to other sources of protein that it's logical why people would incorporate them into their diet.

In some cultures, rats are or have been limited as an acceptable form of food to a particular social or economic class. In the Mishmi culture of India, rats are essential to the traditional diet, as Mishmi women may eat no meat except fish, pork, wild birds and rats. Conversely, the Musahar community in north India has commercialised rat farming as an exotic delicacy In the traditional cultures of the Hawaiians and the Polynesians, rat was an everyday food for commoners.

When feasting, the Polynesian people of Rapa Nui could eat rat meat, but the king was not allowed to, due to the islanders' belief in his "state of sacredness" called Tapu. In studying pre-contact archaeological sites in Hawaii, archaeologists have found that the concentration of the remains of rats associated with commoner households counted for three times the animal remains associated with elite households. The rat bones found in all sites are fragmented, burned and covered in carbonized material, indicating that rats were eaten as food. The greater occurrence of rat remains associated with commoner households may indicate that the elites of pre-contact Hawaii did not consume them as a matter of status or taste.

Bandicoot rats are an important food source among some peoples in Southeast Asia, and the United Nations Food and Agriculture Organization estimates that rat meat makes up half the locally produced meat consumed in Ghana, where cane rats are farmed and hunted for their meat. African slaves in the American South were known to hunt wood rats (among other animals) to supplement their food rations, and Aborigines along the coast in Southern Queensland, Australia regularly included rats in their diet.

Ricefield rats (Rattus Argentiventer) have traditionally been used as food in rice-producing regions like Valencia, as immortalized by Vicente Blasco Ibáñez in his novel Cañas y Barro. Along with eel and local beans known as "Garrafons", Rata de Marjal is one of the main ingredients in traditional paella (later replaced by rabbit, chicken and seafood). Ricefield rats are also consumed in the Philippines, the Isaan region of Thailand, as well as Cambodia. In late 2008, Reuters reported that the price of rat meat had quadrupled in Cambodia creating a hardship for the poor who could no longer afford it. Cambodia exports about a metric ton of rats daily to Vietnam as food.

Elsewhere in the world, rat meat is considered diseased and unclean, socially unacceptable, or there are strong religious proscriptions against it. The British SAS's rule book lists rat as the only meat which its members in action are not allowed to eat in order to prevent them from contracting Weil's disease. Islam and Kashrut traditions prohibit it, while both the Shipibo people of Peru and Sirionó people of Bolivia have cultural taboos against the eating of rats.

Rats are a common food item for snakes, both in the wild, and as pets. Captive-bred ball pythons in particular, are fed a diet of mostly rats. Rats, as food items, are available from many suppliers who supply to individual snake owners as well as to large reptile zoos. In Britain the government in 2007 ruled out the feeding of any live mammal to another animal. The rule says the animal must be dead (frozen) then given to the animal to eat. The rule was put in to place mainly because of the pressure of the RSPCA and people who found it cruel.

In medicine Rats can serve as zoonotic vectors for certain pathogens and thus cause disease, such as Lassa fever and Hantavirus. Rattus rattus, and the rat flea Xenopsylla cheopis, are notorious for their role in epidemics of bubonic plague.

In odour detection Rats have a very good sense of smell and are easy to train, this has led to their use in Landmine and Tuberculosis detection

In culture Ancient Romans did not generally differentiate between rats and mice, instead referring to the former as Mus Maximus (big mouse) and the latter as Mus Minimus (little mouse).

On the Isle of Man (a dependency of the British Crown) there is a taboo against the word "rat." See Longtail (rat) for more information.

In Asian cultures In Indian tradition rats are recognized as the vehicle of Lord Ganesh and a rat's statue is always found in a temple of Ganesh. In the north western Indian city of Deshnoke, the rats at the Karni Mata Temple are held to be destined for reincarnation as Sadhus (Hindu holy men). The attending priests feed milk and grain to the rats, of which the pilgrims also partake. Eating food that has been touched by rats is considered a blessing from god.

In Imperial Chinese culture, the rat (sometimes referred to as a mouse) is the first of the twelve animals of the Chinese zodiac. People born in this year are expected to possess qualities associated with rats, including creativity, intelligence, honesty, generosity, ambition, a quick temper and wastefulness. People born in a year of the rat are said to get along well with "monkeys" and "dragons," and to get along poorly with "horses. The indigenous rats are allowed to run freely throughout the Karni Mata temple.In European cultures European associations with the rat are generally negative. For instance, "Rats!" is used as a substitute for various vulgar interjections in the English language. These associations do not draw, per se, from any biological or behavioural trait of the rat, but possibly from the association of rats (and fleas) with the 14th-century medieval plague called the Black Death. Rats are seen as vicious, unclean, parasitic animals that steal food and spread disease. However some people in European cultures keep rats as pets and conversely find them to be tame, clean, intelligent, and playful.

Rats are often used in scientific experiments; animal rights activists allege that treatment of rats in this context is cruel. The term "lab rat" is used, typically in a self-effacing manner; to describe a person whose job function requires that they spend a majority of their work time engaged in bench-level research (i.e. a scientist or research assistant).

Rat in terminology Rats are frequently blamed for damaging food supplies and other goods, or spreading disease. Their reputation has carried into common parlance: in the English language, rat is often an insult. Rat is generally used to signify an unscrupulous character. Writer/Director Preston Sturges created the humorous alias "Ratskywatsky" for a soldier who seduced, impregnated, and abandoned the heroine of his 1944 film, The Miracle of Morgan's Creek. It is a term (noun and verb) in criminal slang for an informant - "to rat on someone" is to betray them by informing the authorities of a crime or misdeed they committed. Describing a person as "rat-like" usually implies he or she is unattractive and suspicious.

Imperial Japan depicted as a rat in a WWII United States Navy propaganda poster Depictions of rats in fiction are historically inaccurate and negative. The most common falsehood is the squeaking almost always heard in otherwise realistic portrayals (i.e. non-anthropomorphic). While the recordings may be of actual squeaking rats, the noise is uncommon - they may do so only if distressed, hurt, or annoyed. Normal vocalizations are very high-pitched, well outside the range of human hearing. Rats are also often cast in vicious and aggressive roles when in fact it is their shyness which helps keep them undiscovered for so long in an infested home.

The actual portrayals of rats vary from negative to positive with a majority in the negative and ambiguous. The rat plays a villain in several mouse societies; from Brian Jacques's Redwall and Robin Jarvis's The Deptford Mice, to the roles of Disney's Professor Ratigan and Kate DiCamillo's Roscuro and Botticelli. They have often been used as a mechanism in horror; being the titular evil in stories like The Rats or H.P. Lovecraft's The Rats in the Walls  and in films like Willard and Ben. Another terrifying use of rats is as a method of torture, for instance in Room 101 in George Orwell's Nineteen Eighty-Four or The Pit and the Pendulum by Edgar Allan Poe.

Selfish helpfulness —those willing to help for a price— has also been attributed to fictional rats.[20] Templeton, from E. B. White's Charlotte's Web, repeatedly reminds the other characters that he is only involved because it means more food for him, and the cellar-rat of John Masefield's The Midnight Folk requires bribery to be of any assistance.

Some fictional works use rats as the main characters. Notable examples include the society created by O'Brien's Mrs Frisby and the Rats of NIMH, Doctor Rat, Rizzo the Rat from The Muppets, and animated films like Pixar's charming Ratatouille. Mon oncle d'Amérique ("My American Uncle"), a 1980 French film, illustrates Henri Laborit's theories on evolutionary psychology and human behaviours by using short sequences in the storyline showing lab rat experiments.

The Pied Piper, one of the oldest and most historic stories about rats is The Pied Piper of Hamelin, in which a rat-catcher leads away an infestation with enchanted music—the piper is later refused payment, so he in turn leads away the town's children. This tale, placed in Germany around the late 13th century, has inspired the realms of film, theatre, literature, and even opera. The subject of much research, some theories have intertwined the tale with events related to the Black Plague, in which black rats may have played an important role. Fictional works based on the tale that focus heavily on the rat aspect include Pratchett's The Amazing Maurice and his Educated Rodents, and Belgian graphic novel Le Bal du Rat Mort (The Ball of the Dead Rat).

Taxonomy of Rattus The genus Rattus is a member of the giant subfamily Murinae. There are several other murine genera that are sometimes considered part of Rattus: Lenothrix, Anonymomys, Sundamys, Kadarsanomys, Diplothrix, Margaretamys, Lenomys, Komodomys, Palawanomys, Bunomys, Nesoromys, Stenomys, Taeromys, Paruromys, Abditomys, Tryphomys, Limnomys, Tarsomys, Bullimus, Apomys, Millardia, Srilankamys, Niviventer, Maxomys, Leopoldamys, Berylmys, Mastomys, Myomys, Praomys, Hylomyscus, 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 of rats Genus Rattus - Typical rats

Annandale's Rat (Rattus Annandalei) – Indonesia, Malaysia, and Singapore Enggano Rat (Rattus Enganus) – Indonesia Philippine Forest Rat (Rattus Everetti) – Philippines Polynesian Rat (Rattus Eexulans) – Fiji and most Polynesian islands, New Zealand, Easter Island, and Hawaii Hainald's Rat (Rattus Hainaldi) – Indonesia Hoogerwerf's Rat (Rattus Hoogerwerfi) – Indonesia Korinch's Rat (Rattus Korinchi) – Indonesia † Maclear's Rat (Rattus Macleari) – Christmas Island Nillu Rat (Rattus Montanus) – Sri Lanka Molaccan Prehensile-tailed Rat (Rattus Morotaiensis) – Indonesia † Bulldog Rat (Rattus Nativitatis) – Christmas Island Kerala Rat (Rattus Ranjiniae) – India New Ireland Rat, Rattus Sanila Andaman Rat (Rattus Stoicus) – Andaman Islands Timor rat (Rattus Timorensis) – Timor R. Norvegicus group Himalayan Field Rat (Rattus Nitidus) – Bangladesh, Bhutan, China, India, Indonesia, Laos, Myanmar, Nepal, Palau, the Philippines, Thailand, and Vietnam Brown Rat or Norway Rat (Rattus Norvegicus) – worldwide except Antarctica Turkestan Rat (Rattus Pyctoris; obs. Rattus Turkestanicus) – Afghanistan, China, India, Iran, Kyrgyzstan, Nepal, and Pakistan R. Rattus group Sunburned Rat (Rattus Adustus) – Enggano Island, Indonesia Sikkim Rat (Rattus Andamanensis) – Bhutan, Cambodia, China, India, Laos, Myanmar, Nepal, Thailand, and Vietnam Rice-field Rat (Rattus Argentiventer) – Southeast Asia Summit Rat (Rattus Baluensis) – Malaysia Aceh Rat, Rattus Blangorum Nonsense Rat (Rattus Burrus) – India Hoffmann's Rat (Rattus Hoffmanni) – Indonesia Koopman's Rat (Rattus Koopmani) – Indonesia Lesser Rice-field Rat (Rattus Losea) – China, Laos, Taiwan, Thailand, and Vietnam Mentawai Rat (Rattus Lugens) – Indonesia Mindoro Black Rat (Rattus Mindorensis) – Philippines Little Soft-furred Rat (Rattus Mollicomulus) – Indonesia Osgood's Rat (Rattus Osgoodi) – Vietnam Palm Rat (Rattus Palmarum) – India Black Rat (Rattus Rrattus) – worldwide except Antarctica Sahyadris Forest Rat, Rattus Satarae Simalur Rat (Rattus Simalurensis) – Indonesia Tanezumi Rat (Rattus Tanezumi) – Afghanistan, Bangladesh, Cambodia, China, Cocos (Keeling) Islands, Fiji, India, Indonesia, Japan, North Korea, South Korea, Laos, Malaysia, Myanmar, Nepal, Pakistan, the Philippines, Taiwan, Thailand, and Vietnam Tawi-Tawi Forest Rat (Rattus Tawitawiensis) – Philippines Malayan Field Rat (Rattus Tiomanicus) – Indonesia, Malaysia, the Philippines, and Thailand R. Xanthurus group Bonthain Rat (Rattus Bontanus; obs. Rattus Foramineus) – Indonesia Opossum Rat (Rattus Marmosurus) – Indonesia Peleng Rat (Rattus Pelurus) – Indonesia Rattus Salocco Yellow-tailed Rat (Rattus Xanthurus) – Indonesia R. Leucopus group (New Guinean group) Arfak Rat (Vogelkop Mountain Rat), Rattus Arfakiensis Western New Guinea Mountain Rat, Rattus Arrogans Sula Rat (Rattus Elaphinus) – Indonesia Spiny Ceram Rat (Rattus Feliceus) – Indonesia Giluwe Rat (Rattus Giluwensis) – Papua New Guinea Japen Rat (Rattus Jobiensis) – Indonesia Cape York Rat (Rattus Leucopus) – Australia, Indonesia, and Papua New Guinea Eastern Rat (Rattus Mordax) – Papua New Guinea Moss-forest Rat (Rattus Niobe) – Papua New Guinea, Indonesia New Guinean Rat (Rattus Novaeguineae) – Papua New Guinea Arianus's Rat, Rattus Omichlodes Pocock’s Highland Rat, Rattus Pococki Spiny Rat (Rattus praetor) – Indonesia, Papua New Guinea, and Solomon Islands Glacier Rat (Rattus Richardsoni) – Indonesia Stein's Rat (Rattus Steini) – Indonesia and Papua New Guinea Van Deusen's Rat (Rattus Vandeuseni) – Papua New Guinea Slender Rat (Rattus Verecundus) – Indonesia and Papua New Guinea R. Fuscipes group (Australian group) Dusky Rat (Rattus Colletti) – Australia Bush Rat (Rattus Fuscipes) – Australia Australian Swamp Rat (Rattus Lutreolus) – Australia Dusky Field Rat (Rattus Sordidus) – Australia, Indonesia, and Papua New Guinea Pale Field Rat (Rattus Tunneyi) – Australia Long-haired Rat (Rattus Villosissimus) – Australia

Wiki & direct gov

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