Rats

Description

The most common species in the UK is the Brown Rat, also known as the ‘common’ or ‘sewer’ rat.  The brown rat has a blunt nose, small furry ears and is generally a brownish-grey colour on top and slightly lighter underneath.  On average, they will live between 6-18 months, in that time reproducing up to 7 times.  Each litter can consist of between 6-14 young.  The brown rat ranges from 25-45cm in length (including the tail).  Their eyesight is generally poor, but they have excellent hearing.

Brown rats are omnivorous - they will eat almost anything – and can consume about 30g of food per day, which is about 1/10th of their average body weight.

Distribution

Rats are a worldwide pest, they are very adaptable and known to spread life threatening diseases as well as causing structural damage in the areas they infest.

Significance

Rats have been known to cause major structural damage to residential and commercial properties as well as to services such as power supplies.  Rats have also been known to spread the following diseases:

• Listeria and Pasteurella, which cause food poisoning and stomach bugs
• Leptospira, which causes flu-like symptoms
• Worms, which can lead to general ill health
• Cryptosporidia and Taxoplasma, which cause diarrhoea.

What to look out for

Rats can live indoors and outdoors so evidence can be found in either location.  However they are more likely to be found outside or in buildings such as garages or sheds.  If rats do enter your house, they are more likely to be found in cavity walls, lofts and basement areas, and under suspended wooden floors.  If you suspect you have rats, indoors or out, look out for the following:

• Rat droppings, which are about 1-2cm long and look like dark brown jelly beans.  These are distinctly different from mice droppings, which are much smaller and look like small, dark brown grains of rice.
• Droppings in and around the edges of garden sheds, compost heaps, pet hutches and bird tables.
• Burrows (rats are burrowing animals) that can be found in gardens, near rubbish, sources of food and compost heaps, which provide rats with ideal harbourage.
• Smears along surfaces where you suspect rats have been running.  They are habitual animals, and will follow specific paths.  These smears are normally caused by the build-up of grease from their fur.
• Rats secrete urine as they move and eat, so be aware of any unusual smells.
• Gnawing damage to containers, pipes or structures.
• Flattened vegetation and/or worn earth.
• Damage to packets of food, electrical cables, gas and water pipes, woodwork and shredded paper which is used for nesting.

Control

The best approach to dealing with or preventing infestations is the combined use of rodenticides, proofing and good hygiene practice.

Rodenticides

Only use commercially prepared rodenticides.  These are available at all good hardware and DIY stores.  Any bait is best placed in areas where contact with rats is most likely to occur (see above).  Ideal areas to place bait include areas behind cookers, under sinks, behind kitchen kickboards, in the loft, under raised wooden flooring, in electric/gas cupboards, along the outer walls and entrances of outhouses/garages/sheds.

Regularly check the bait to see if there is any evidence of bait being taken or eaten.  If there is, top up the bait accordingly.  Continue baiting until there are no further signs of rats.  If the bait is left out for long periods, rats have been known to build up resistance to rodenticides.

Do not expect immediate results.  It can take 3-10 days for rats to die once the poison has been ingested.  However, if there are alternative sources of accessible food, rats will avoid the poison altogether and go for the tastier alternative.

CAUTION: children and pets should be prevented from accessing the bait.  Do not place baits within 1 metre of gas fires and always make sure there is an unimpeded flow of air to the back of the fire.

Good hygiene practice

Controlling and preventing rats can also depend on:

• Good building maintenance – such as filling in holes and/or proofing openings  bigger than 2.5cm in diameter.
• Removing garden rubbish, debris, old furniture etc which can provide harbourage that would attract rats.
• Maintaining a tidy garden.
• Removing food scraps from gardens or alleyways.
• Do not feed birds on the ground – use specialist feeder tables.
• For food stored in sheds and garages, use sealed metal or plastic containers to prevent rodent access.
• Use brush strips where there is a gap under a door.
• Use black bins to store rubbish.  Rats will chew through bin bags.  Bins are available from most DIY stores.

If you do not wish to carry out treatment yourself, professional pest control companies listed in Yellow Pages will be able to help.

Alternatively, John O’Connor (GM) Ltd deliver our pest control service and they will advise you of the treatment required and the charge.