Pest News   |   May 3, 2021

The importance of proofing and exclusion as part of your integrated pest management plan

This may sound odd coming from a pest control manufacturer, but the primary aim is always to avoid a rodent infestation as rats and mice can be difficult to control once they get established. But we understand that as PMP’s you are only called when a customer has a rodent problem that needs your intervention! Proofing and exclusion work is therefore an essential part of your integrated pest management plan to ensure that small problems do not become large infestations. Here we set out the first 3 steps of our PelGar 6 Step Rodent Control Plan that you should carry out before you implement any baiting regime, so that you are not facing an uphill battle while ensuring you have sustainable control.

Step 1 – Site Survey

Your initial investigations need to be thorough to determine what you need to know about the pest you are facing and what you need to know about the site itself. On a map of the property you should, at a minimum, mark out:

  • signs of rodent activity including actual sightings, footprints, earthworks and runs, fresh droppings, grease smears, urine trails, gnawing, chewing and any other evidence.
  • primary and alternate sources of food and water (including garbage areas).
  • harbourage points for sleeping, hiding, eating and breeding.
  • the degree of public access to the site and especially the presence of any children.
  • the presence of non-target animals such as pets, farm livestock and wildlife.
  • evidence of poor housekeeping and hygiene.
  • obvious building defects such as broken pipes, defective sewer chamber covers, bad construction, surface water gullies and so on.
  • Environmental factors including soil and water courses that could be contaminated by chemical baiting.

It is always recommended that you take photographic evidence for your own purposes as well as for the customer.


Your initial site survey becomes the baseline for future inspections and will later also contain the map of bait station placement so that you can record results and adjust as necessary.

Step 2 - Tidy Up

Sounds obvious but rodents quickly get hold in untidy places! Like all animals, rodents need the triangle of food, water and harbourage to survive. These are simply more plentiful in ill-kept environments, but by reducing the availability of any one of these (and ideally all 3) you immediately curtail an infestation and also encourage rodents to feed on the selected bait. These essential hygiene measures fall in to two main areas:

Removal of food and water

Easy access to free food and water is an open invitation for rodents, so removal of all spills, spoiled and stored foodstuffs will have an immediate effect. Ideally food should be placed in rodent proof bins and containers, but if this is not possible make sure food is stored at least a foot away from walls and off the ground to make access harder. Remove all free sources of water, especially where water may be standing or pooled unnecessarily - rats need to drink once per day to survive but mice do not.

Removal of harbourage

In and around the buildings there will be a wide range of materials and habitats that provide easy, concealed harbourage for rodents to live, hide and breed. Remove and destroy all garbage in and around buildings and ensure that potential nest building materials are difficult to access. Outside of buildings vegetation should be cleared to provide an open perimeter for natural predators - cut long grass back, trim hedge undergrowth and make sure ditches and banks are properly maintained to make them less attractive to rodents. Also check along drainage systems and any other links between buildings for any harbourage and concealed movement.

Whilst you are tidying up it is worth remembering that rodent droppings and grease smears are markers for the community to follow, so you may wish to remove them to cause disruption or you may prefer to use them to your advantage when placing bait stations.

Step 3 – Proofing and Exclusion

The simple aim is to keep rodents out of vulnerable buildings. Mice can squeeze through a hole the size of your little finger (or a US dime) and rats through a hole the size of your thumb (a US quarter)… finding these points of entry is much easier in a clean and tidy environment! Some points of ingress will be obvious, especially around doors and windows, but pay special attention to parts of the building where joists, pipes and cables enter and leave; any holes made to accommodate these are easy access for rodents. And don’t forget sewers, even small pipes are a rodent super-highway.


Proofing and exclusion needs to be practical and realistic – rodents are quick to exploit any faults and weaknesses so a sound understanding of rodent behaviour is essential; think like a rodent!

  • Repair leaking taps and pipes inside and out to deny rodents water.
  • Proof drainage and sewer pipes by fitting grilles, flaps, crushed wire mesh or other suitable materials.
  • Seal the bottom of doors, especially if they have been chewed, with metal kick plates and make sure they are kept shut.
  • Check all windows are maintained and do not provide easy points of entry.
  • Pay attention to broken roof tiles, brickwork and foundations as these provide easy access into loft and cavity wall space.
  • Make sure all foodstuffs are kept in rodent proof containers, or proof the containers they are in, and ensure any spills are cleaned up immediately.
  • Seal any gaps, cracks and holes in wood, brick, PVC or metal with RodentStop exclusion compound – its unique combination of polymers and metal filings is a permanent barrier that rodents don’t want to gnaw through and its far more effective than wire wool.
  • Make sure your customer understands the importance of avoiding the creation of rodent access routes and harbourage when they are moving things around or undertaking maintenance and building work.
  • If you are tackling a large infestation consider leaving a well-used, easily accessible rodent ingress point available to make baiting easier.

In rural environments rats will seek warmth and food in the autumn and winter, so proofing work in the summer will help prevent any infestation. In urban environments it can be year-round, remember that throughout breeding season they will be on the hunt for high calorie foods as that can be used to your advantage. Mice generally live within the fabric of buildings year round and, due to their size, can be harder to proof against but even limited exclusion work will reap benefits.


Rodents need three things to survive: food, water and harbourage. Restricting the access to any of these three will make life more difficult for them to thrive and they will leave the area. Measures to protect vulnerable buildings by tidying up and preventing access to food, water and harbourage will have little or no impact on the surrounding non-target species including pets, livestock and wildlife and so should always be implemented first as part of your IPM plan.


Once these 3 steps have been carried out you can set up regular and routine inspections to identify and rectify any future faults or damage. Make sure to update your plan of the site to include all the measures undertaken and chat it through with the customer so that they, and others on the site, understand what you are doing and why to avoid any unintentional undoing of your good work.


Even if you need to move on to a baiting program it should be noted that killing rodents can only provide short term control of populations if proofing and exclusion work has not been carried out first or in tandem – otherwise you are simply creating a welcoming, empty home for the next population of rodents to move in to. Sustainable control can only be achieved by reducing the rodent carrying capacity of the environment.


Proofing and exclusion work may be costly and require frequent maintenance, but good housekeeping and building upkeep should be everyone’s priority as a lack of such is precisely what invites pests – it is far easier to prevent an infestation than eradicate one.