Rats

Common Name:Norway rat or Common rat
Scientific Name: Rattus norvegicus

Common Name:Roof rat or Ship rat
Scientific Name: Rattus Rattus

Introduction:Rats are worldwide pests and can adapt to any temperature or climate. Due to their capability the compete with man for food, water and cause lots of cause lots of structural damages such as fires, floods and also spread life threatening diseases to humans. There are mainly two types of rats found in Britain: the Norway rat and the Ship rat. The Norway rat is most commonly seen throughout the country.

The Norway rat (rattus norvegicus): Also known as the common rat, it was recorded in Britain from the early eighteenth century. The adult weighs on average 335 grams and about 350mm - 450mm long (tip of nose to tip of tail). The fur is harsh and shaggy, the upper head is brown and black and grey or off white underneath. Their droppings are ellipsoidal capsule in shape and about 20mm long and found in groups and sometimes scattered. Norway rats are widespread in both urban and rural areas, and can be found anywhere offering food and shelter. They have a very acute sense of hearing and smelling and with all these attributes are colour blind. They live both indoors, outdoors and in sewers. Common rats can jump up to 700mm. They are efficient burrowers and form holes which are on average 100mm in diameter. Burrowers can be found around the outside of buildings, embankments, rubbish tips, overgrown gardens, etc. Rats are generally active at night and can be seen searching for food and water during the day.

Roof rat (Rattus Rattus): Commonly known as ship rat or black rat they have very much in common and very little difference to the Norway Rat. Roof rats are non burrowing and very agile climbers. They mainly nest in walls, attics, vines and trees. They are rarely found in sewers. The adult weighs on average 225 grams and about 330mm - 470mm head to tail. Their fur is much smoother and usually black or grey in colour. Roof rats have pointed snouts, their droppings have a spindle or banana shape about 12mm in length and their eyes are large and prominent.

Biology:Rats reaches sexual maturity at age 2- 3 months and are capable of reproducing. Rats can have on average 7 litters per year with an average of 6 to 10 young. When, the female becomes sexually receptive, her scent attracts the males but can only be receptive for a maximum of 12 hours each cycle. Mating is normally brief and can take place with a number of males. Pregnancy lasts an average of 24 to 28 days. Young rodents are born blind and hairless. They become fully furred, eyes open and their incisors showing in 14 days. They are weaned at about 3 to 4 weeks. Both species of rats live an average of 9 to 18 months. Although females tend to live longer than males, both species have been proven to live much longer under natural conditions of up to 2 years. Rats have rather poor vision and are colour blind, but their sense of hearing, smelling, touching and tasting are excellent. Touching is by their long whiskers (vibrissae). Both species are good climbers, runners, jumpers, and swimmers. Rats require food and water every day and they consume up to 25-30 grams of food.

Potential Harm: The most commonly thought disease, involving rats is the plague which is transmitted by rodent fleas leaving an infected rat and then attacking man. Rats contaminate food with their droppings, urine and hair. Other transmittable diseases include murine typhus by fleas (also possibly by droppings and urine. Leptospirosis, also known as canicola fever, swamp fever, swineherd's disease, or sewerman's flu, is a bacterial infection resulting from exposure to the Leptospira interrogans bacterium. It is an acute form of human infection known as Weil's disease, which is caused by rat urine or droppings in food and water, (a rare infection which starts with influenza like symptoms which can be fatal), rat-bite fever through rat bites and food poisoning or Salmonellosis by droppings (food-borne illness causing diarrhoea and vomiting). Other rat-borne diseases are yersiniosis, toxoplasmosis, crytosporidiosis, toxocariasis, Qfever, hantavirus. Another problem is tropical rat mite dermatitis, which is caused by these mites when they feed on humans. These diseases are not only found in Britain but worldwide. Rats are a major public health-hazard; in Britain today they cause structural damage to buildings, flood defences, farms, fields, bridges and our personal homes. Their gnawing and burrowing activities can cause fires and floods to our buildings and land.

Food sources: Rats are omnivores, they will try to get the food both from indoors and outdoors. Indoors they will consume seeds, grains, nuts, pet foods, cereals, bread, chocolate, and meals consumed by humans. Outdoor sources of food are bird feeders, vegetable gardens, farms, waste food-bins, pet food, and dump sites. They will invade houses, pantries, garages, stores, warehouses and shops or anywhere they can get food and water for a meal.

Control

Trapping: In the event of an infestation a large number of traps should be used in order to be effective and successful. Place the traps at an angle in the area of the infestation, rat runs or tracks. Suggested bait which can be used in traps e.g. fruit, chocolate, peanut butter, or bread.

Rodenticides: The best and most effective way to deal with a rat infestation. Baits contain different types of active ingredients and pest exterminators in London can chose which type they will use when bating (first generation and second generation anticoagulant). When treating rats use enough bait stations as necessary or rats will consume much more food than mice. However if rats find that the bait is not palatable or have access to a better food source, or bait station has been shifted frequently, then they will not take the bait. Obviously this leads to greater problems. Rats need to get used to anything new and will not feed from a bait station until they have gotten used to it being there. It takes longer to start treating a rat infestation so essential food source can be denied. Once the application has been corrected, if there are still no takes from the bait station, these are to be considered: are they bait resistant, bait shyness, neophobic reaction and other food sources? Other method of controlling could be integrated pest management (IPM).

Be careful while using any trap or rodenticide. Ensure that bait station is place in a safe location to avoid not targeting species, humans and pets. Please read the label carefully before use.