
Order: Rodentia
Family: Muridae
Norway Rat: 220-260mm long
CHARACTERISTICS:
Brownish or greyish rodents with a tail approximately as long as the body. Omnivorous, often live in or around buildings.
SPECIES CHARACTERISTICS:
Norway Rat (Rattus norvegicus)
Common names are Norway rat, Common rat and Brown rat. Adults: 220-260mm long; tail length 160-200mm; weight 150-450g; droppings are approx 20mm long. Upper brown body with a white, yellowish belly.
AREAS WHERE FOUND:
Norway Rat (Rattus norvegicus) - The Norway rat originated from Central to East Asia. It is thought to have arrived in Europe later than the Black rat, c. 16-17th century.
IMPORTANCE AS A PEST:
Human health: Carriers of over 45 types of diseases including spirochaetes causing Weil’s Disease (Leptospirosis), Salmonella, E.coli, enteritis, listeriosis, rickettsiosis, dysentery and many others. Contamination of water and food. Contamination of environment
Construction: Damages in buildings: In sewers, dikes etc., in electric facilities & cables and in communication.
Direct food losses: Field crop losses. Stored food and food prod. chain losses.
Indirect food losses: Packaging destruction, spillage. Contamination with faeces.
Animal production: Feed losses and spillage. Vector and reservoir of pathogens.
LIFE-CYCLE:
Norway Rat (Rattus norvegicus):
The Norway rat reaches sexual maturity in about 2-3 months and are reproductive for one year. Norway rats can breed throughout the year if conditions are suitable. The gestation period is only 21 days and a female can produce up to a maximum of five litters a year. 14 pups per litter is the maximum, although six is the average.
CONTROL:
An integrated pest management approach using a combination of control measures (e.g. improving hygiene, proofing) is necessary in order to gain control of a rodent infestation. Baiting alone is not sufficient. To effectively control rat and mouse problems there are six golden rules which should be followed:
Inspection / Assessment of infestation
A thorough survey of the infested site before treatment begins is an essential key to success when using any rodenticide. It is important to determine the exact source of the infestation so that the problem can be tackled at source. Typical signs of an infestation are the smudge marks left by a rodent’s oily hair, its droppings and any damage to goods or structures. Draw up a simple site plan or location list identifying areas of particular concern pertinent to the site and retain this on file.