Rats Fact Sheet
Infestation Identification: Rats are rodents with pointed noses, large ears, they are covered in fur apart from their tails which are usually hairless and scaly which are almost the same length as their bodies. There are many different species of rat, which vary in size and colour, the most common species in the UK are Brown Rats and Black Rats.
Brown Rats are the most common rats, they have dark grey or brown coarse fur but the colour can differ slightly. Adults lengths are 18cm to 25cm not including the tail lengths which are 15cm to 25cm.
Black rats have black to light brown coarse fur, with a slightly lighter shade of fur on the stomach. Adults lengths are 12cm to 19cm not including the tail lengths which are 15 to 22cm.
You will notice their faecal matter scattered around the areas they have been, the droppings are brown or black, curved cylindrical shaped and between 10mm to 20mm long, they usually produce 40 droppings per day. You may also notice smear marks if they have run against walls or on surfaces, this is due to the oils from the rats fur. Rats are continuously gnawing on food packaging, wood, brickwork, cardboard, wiring, pipes and furniture, the list is endless of items they will chew and cause damage to, which can be extremely expensive to repair and very dangerous because they can cause electrical fires and other fatal issues. Rats chew because they need to wear down their incisor teeth grow continuously.
Rattus (Rat), Rattus Norvegicus (Brown Rat), Rattus Rattus (Black Rat)
Brown Rats are also known as the Common rat, Street rat, Sewer rat or Wharf rat.
Black rats are also known as Ship rat, Roof rat, House rat.
Diet: Rats will basically eat anything that they can chew through, however cereals are a substantial part of their diets. Outdoors they feed on berries, fruit, nuts, seeds, insects, fungi, and snails. Rats living in homes will eat any food which is left unprotected, they gnaw on food packaging, wood, brickwork, cardboard, wiring, pipes and furniture, the list is endless.
Habitat: Rats can live indoors and out, if they live outside they will make burrows underground or find shelter in places like sheds, garages, greenhouses, farms and sewers. For rats that live indoors, they will build nests in lofts, under kitchen units, under flooring, in wall cavities, airing cupboards and other places they will not be disturbed by humans. They can gain access into spaces as little as 5mm.
Prevention: The most important prevention method is to ensure that all food stuffs are cleaned and cleared after use and that bins are cleaned, emptied and always covered. It can be difficult to prevent rats entering your property if you don’t know what to look for and where. Because rats are limited by the size of their skull, any hole which is 5mm or more is a potential way for mice to access your property.
Life Cycle: Rat breed throughout the year in dwellings indoors, females can start breeding at approximately 5 weeks old. Their gestation period is approximately 21 days, producing up to 14 per litter although there are usually between 6 to 9. Having up to 5 litters a year can mean that 30 to 70 young per year. Within a year 2 rats can multiply into 15,000. Females can become pregnant immediately after giving birth, whilst still nursing the new litter.
General Information: The life span of rats is between 10 and 15 months, however in the wild they can survive for up to 36 months. Rats can give birth when they are 8 weeks old and can have up to 70 young a year. Rats are nocturnal so they are mainly active at night and are very good swimmers both under the water and on the surface.
Treatments: There are amateur poisons which can be purchased in shops, however, these are often not strong enough to eradicate rats, especially large infestations. The reason for this is because only low doses of the active ingredients like Difenacoum and Brodifacoum are used, professional rodenticides have a much greater strength. Snap traps are another method which can be used and baited with chocolate, raisins or something similar, however, they will only catch one at a time, so infestations will continue to grow.
Under the right conditions 2 rats can multiply into 15,000 rats within a year.
Rats can live in most habitats providing there is enough food and a water source.
They produce 40 droppings per day.
Rats spread numerous diseases such as Salmonella, E. coli, Weil’s Disease, Tuberculosis, Cryptosporidiosis and Hantavirus.
Rats carry fleas, ticks and lice, spreading more diseases.
Rodent faecal matter can trigger allergies and cause asthma attacks.
Rats are nocturnal and are mainly active at night.
Brown rats can jump horizontally 120cm and vertically more than 77cm and are good at climbing
Females can start breeding at approximately 5 weeks old.
Because rats are limited by the size of their skull, any hole which is 5mm or more is a potential way for mice to access your property.