Controlling Rats and Mice - A Guide to Preventing Infestations

The house mouse and brown rat are common pests.  Rats are efficient burrowers and can burrow for several metres horizontally.  Both rats and mice are good climbers and can climb vertical walls and "shimmy" up between walls and drain pipes.  Rats are also excellent swimmers and have been known to enter premises through the water traps of the toilet bowl when infestations occur in the main sewerage system.

There are three main reasons rodents must be controlled: They can transmit diseases; contaminate food and can cause damage by gnawing woodwork, water pipes and electric cables.

How can I prevent rat and mice infestation?

A rat needs three things - food, shelter and water.  If it can get these it is likely to stay.

Householders can assist in preventing an infestation by taking a number of simple precautions:

  • Keep your gardens free from food i.e. pick up any fallen fruit and residue from bird feeders.
  • Do not put food onto a bird table.
  • Feed birds sensibly by using feeders with a catch tray to stop debris falling onto the ground.  Place small amounts of food in feeders to ensure they are emptied daily.
  • Do not throw unwanted food waste into your garden.
  • Keep your home in good repair; rats only need a gap of 15mm to access buildings.
  • Remove potential nesting sites by keep gardens clean and tidy and by cutting back overgrown areas.
  • Ensure drain covers are in place and in good repair.
  • Seal gaps around heating and water pipes.
  • Ventilation bricks and slots should already have a fine wire mesh protection.  If this is worn, replace it externally with 3.15mm insect mesh.
  • Do not leave household waste where rats can access it - close bin and composter lids.
  • If you have a compost heap, position it on a hard surface such as open jointed bricks, paving slabs or a fine steel mesh which will allow the liquids to drain away.
  • Secure any gaps beneath your external buildings such as sheds and garages with galvanised wire mesh.
  • Climbing plants which reach gutter level will allow rodents to access your roof space and from there into the wall cavity and the rest of your home.

Fallen food from bird feeders is highly desirable to rats, it is a good idea to use bird feeders with a catch tray.