Rats are a worldwide pest due to their capacity to cause structural damage, to spread
life-threatening diseases, and to compete with man for food.
The species most commonly
found in Europe is known as the Norway Rat (Rattus norvegicus). A less commonly found
species, the Black or Roof Rat, (Rattus rattus), is largely restricted to port areas.
Rats live alongside man, invading his buildings and eating his food. Rats transmit
disease which are potentially fatal to man such as Weil's disease and murine typhus.
They also carry organisms which can damage man's health such as Salmonella bacteria,
viruses and parasites such as nematodes and worms.
Damage by rats to the fabric of
buildings can be costly. Fires can easily be started after a rat has gnawed a cable.
Gas and water pipes are also at risk and rat burrowing can undermine foundations
and damage water courses.
Common Names: Norway rat; Common rat; Brown rat; Wharf rat; Sewer rat Adult Weight:
300 grms Length (head + body): 200-250 mm Length (tail): 150-200mm, shorter than
head and body. Fur, colour: Harsh and shaggy. Brown and black on upper head and body,
grey or off-white underneath. Ears, hearing: Thick, opaque, short with fine hairs.
Excellent sense of hearing. Eyes, sight: Small. Poor sight, colourblind. Snout, smell
and taste: Blunt, Excellent sense of smell and taste. Droppings: In groups, but sometimes
scattered. Ellipsoidal capsule shaped, about 20mm long. Habits, habitat: Does burrow.
Lives outdoors, indoors and in sewers. Nests in burrows. Can climb though not agile.
Very good swimmer. Conservative, somewhat predictable in habit. Will avoid unfamiliar
objects, e.g. bait trays, placed on runs, for some days. Range 50 metres. Feeding
habits: Omnivorous, more likely to eat meat than Rattus rattus. Consumes up to 30
grams per day, drinks water or eats food with high water content. Life cycle: Span:
9-18 months. Sexual maturity: 2-3 months. Litter size: 8-10 offspring. Maximum reproduction
rate: 7 litters per year.