How to Rodent Proof Your Home

Prevention is always better than cure, so if you want to keep rodents out of your home, a bit of rodent proofing is required.

The challenge in preventing rats and mice entering a building is that they can squeeze through the smallest of gaps. As a guide, a rat can squeeze through gaps as small as the end of your thumb and a mouse can squeeze through gaps as small as the end of your little finger!

Common rodent entry points

When looking around the building, it is important to look at all the potential gaps, ensuring you don’t miss any small gaps.

These are the common entry points:

• Vents
• Entry points of utility pipes
• Roof and eaves
• Sub-floor (if you have one)

How to block entry points?

Blocking potential rodent entry points is tricking, as rodents will often gnaw through many materials or pull out any loose material used to block holes.

The type of material depends on the entry point to be blocked. The common materials used to block entry points are:

• Steel wool
• Caulk / expanding foam
• Soil metal sheet or wire netting

All metal sheets or netting needs to be at least 26 gauge (0.4mm thick). The dimensions of squares in netting should be no more than 6.5mm x 6.5 mm.

How to make your home less attractive to rodents?

Eliminating sources of food will make your home far less attractive to rodents:

• Clear away dirty dishes after use and keep the kitchen clean
• Keep any cereals in rodent proof containers
• Don’t leave petfood out (including bird food)
• Ensure garbage is placed inside bags inside bins with tight fitting lids

Not only do rodents like to have lots of hiding places to nest in, but as they are always worried about predators, they tend to avoid open spaces – running around the edges of rooms or using vegetation or other obstacles to hide amongst when travelling from A to B.

If you can keep the area around the building free of obstacles, rodents will often not dare to run across the open ground to access the building.

• Keep belongs away from the perimeter of the building and limit any storage under the house.
• Remove vegetation from the perimeter of the building.

Specific tips for rat proofing

There are two types of rats in Sydney, the roof rat and the sewer rat. As their name suggests the roof rat is often found above ground, living in trees and roof voids. The sewer rat tends to be found at ground level. Standard rodent proofing options work for the sewer rat, but a couple of extra actions need to be taken to keep roof rats out of buildings.

• Make sure any branches overhanging the roof are trimmed back.
• Place metal cones round any vertical building structures (eg. veranda poles) to prevent rats climbing up the structure to access the roof. They need to be at least 30cm in diameter and positioned at least 1m above the ground.

Specific tips for mice proofing

Mice only travel a few metres from their nest to their feeding sites. So, if you have a mouse problem inside your house, there will be a nest nearby. In addition to the standard rodent proofing actions, it is a good idea to eliminate any potential mouse nesting sites under or inside the house. Cardboard boxes are a favourite, especially if they are stored in less frequented areas of the house.

Of course, if the pesky rodents have already got into your house, you will need a professional rodent control treatment.