The Rat

Britain has two kinds of rat:

• The Ship Rat (or black rat) is rare in the UK.
• The Common Rat (also known as the brown or sewer rat), is the most abundant and widespread species found throughout the UK and described further on this webpage.

Description and Lifestyle

An adult rat weighs 100-500 grams, measures about 24 cm (excluding tail) and is brown/back with grey fur underneath. It's tail is shorter than the head and body together. In comparison, the house mouse weighs around 30 grams and is 10 cm long (excluding tail), they have large ears in relation to their body with small feet and a tail which is longer than their body.

All rats need to survive are shelter, food and water.

• They are efficient burrowers and favour compost heaps and the ground underneath hedges and sheds, where they will dig shallow burrows and form nests with dry grass and leaves - in houses they nest in wall cavities and beneath floor boards.
• They are good climbers and can climb vertical brick walls.
• They are good swimmers and at home in sewers where they have food, water and shelter.
• Their front teeth grow continuously. To keep teeth to a useful length they gnaw on hard objects all the time e.g. lead water pipes, brickwork, electric cables, wood etc.
• They are usually active at night but may also be alert in the day.
• They usually have well worn runs between their living area and source of food and water.
• Rats life expectancy is around one year, during which time a female will typically breed five times with an average litter of 8. Female rats will have their first litter at the age of 4 months.

Rats can be major hazard to health as they can spread many forms of disease (especially through droppings and urine). Some of these diseases, such as leptospirosis, can be fatal to man although incidences are rare.

They may eat food which is intended for human consumption and their gnawing can cause structural damage to woodwork, water pipes, electric cables etc.

Signs of Infestation

• damage caused by gnawing - packaging will often show tooth marks which will indicate whether it is a rat or a mouse.
• holes made by the rats in doors and walls, and the entrances to nests, are about 80mm ( 3 inches) in diameter, and nests may be made in wall and floor cavities.
• rat runs - once the best route has been established, rats tend to use this "run" frequently and it will become soiled with the grease and dirt and be very apparent in even moderate infestations.
• smears and droppings - a good indication of the size of infestation and how long it has been there.
• footprints can be seen on soft or dusty surfaces.

Pest Control

Elmbridge Borough Council provides a pest control service for the treatment of rats.

If you would like to take advantage of this service please visit our |pest control webpage where you can contact us to arrange a convenient appointment.

If you wish to undertake treatment yourself, remove their food, water and shelter.

The infestation should be controlled using poison bait, which can be purchased from chemists, hardware shops and garden centres. To be effective, baits must be readily available for the rat, but should not be accessible to other animals or humans, and extra care is needed if there are children or pets present - safety instructions on the packaging must be adhered to. It is essential that all other food sources are removed in order to force the rats into eating the poison bait.

It takes several days before rats will feed freely and all baits should be removed when no more poison is being taken. Rats that have taken bait will return to their nest and die. A dead rat can smell but this should disappear after a short while and we don't recommend attempting to find the nest as this usually proves very difficult. Repair of any damage caused by a rat infestation may be required we recommend proofing the premises to prevent further access to the property. |Rodent proofing is another service that Elmbridge Borough Council can undertake.

Rat traps (similar to mouse traps but larger) are not recommended as they can cause injury if set off by mistake, and they have the disadvantage that caught rats have to be disposed of.

Further information

• |Rat information sheet
• |Rodent proofing your property