Brown Rats

Learn about the brown rat

Brown rats can grow up to 40 cm in length and between 350 to 500g in weight. They have blunt noses with small ears and a thicker body when compared to the Black Rat (Rattus rattus). Commonly they have a reddish/brown fur on their backs with a lighter coloured belly, however Rats colours vary greatly.

Their favourite foods are cereal products, although they will eat almost anything and their daily diet usually consists of around 30g of food and 60ml of liquid. A great deal of damage is done by them gnawing electric cables, ripping open packets and fouling food-stuffs with their urine and droppings, which presents a real danger.

Rats generally have 7 or 8 young per litter and 3 to 6 litters a year, with a gestation period of about 3 weeks. They sexually mature in only 10 to 12 weeks, meaning that the Rat population can rise at a truly astounding rate.

Rats can live practically anywhere providing they can find food, water and shelter. In your home, Rats will live in loft spaces, wall cavities, cellars or under floorboards and in the garden they will live under wooden sheds (their favourite place), compost heaps, grassy banks or under ponds. Rats are also commonly found living in sewer systems and are very good climbers and swimmers.

Facts About Brown Rats

Are Rats Dangerous? – In a word Yes. Rats can transmit many diseases to humans. Weils Disease (Leptospirosis) being the commonly known one, causes flu like symptoms and in some cases is fatal. However rats can carry many more chronic diseases including Salmonella, Plague, Tuberculosis, Cryptosporidiosis, E.Coli & Foot and Mouth Disease.

Rodents carry diseases that may be serious or even life-threatening to people. These may be caught by contact with surfaces or water contaminated with rodent urine. You should wear waterproof gloves when working in areas that may be infested. Cover cuts and abrasions on exposed parts of the body with waterproof dressings. Wash exposed skin thoroughly before eating, drinking or smoking and after completing work. If you cut yourself, clean and dress the wound immediately. If you regularly work in rodent-infested areas, your employer should provide you with the HSE pocket card, Leptospirosis: You may obtain one from HSE Books.

How do I know I have Rats?

  • Rat Droppings – They can be 12mm long and resemble a 'spindle' shape
  • Rat Tracks – Rats travel along the same routes and leave trails through the grass
  • Rat footprints and tail swipes – These are usually seen on muddy or dusty surfaces
  • Smear marks – The grease and dirt from Rat coats can be seen on corners of walls & surfaces
  • Rat Burrows – The entrances are approximately 10cm in diameter & generally found at the side of sheds etc.
  • Rat Gnawing – Rats gnaw all the time, even or non food materials to wear down their front teeth.

Methods of Control

The days of the Rat Catcher are more or less gone, modern methods of control are more specialist but highly effective. Resistance to anticoagulants has been confirmed in some rat populations in agricultural areas, although the position in urban environments is unknown. Treatment failures are more likely to be due to inappropriate bait, inadequate quantities of bait, poor bait placement, bait shyness or re-invasion from surrounding areas. Legislation lays down strict guidance for the control of Rats, this is for several reasons including the risk of rodenticides falling in to the wrong hands or affecting non target species, resistance and contamination. Apart from transmitting disease, rats can cause damage to buildings and other structures through gnawing and burrowing.

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