The first line of defence against rodents is simply to exclude them from a property by taking common sense precautions.
Rodent damage can be very costly in commercial situations – not only to buildings, equipment and electrics, but contamination of food and stock can be significant. Although baiting is a common solution for rodent problems in commercial situations, without a robust rodent management plan in place, there is the danger of having to use excessive bait with often poor results – not good for profit or the customer!
Bell’s recommended rodent pest management program consists of five parts:
- Inspection and identification
- Baiting and trapping
- Population knockdown
- Exclusion and sanitation
- Monitoring and maintenance baiting.
Inspection and identification is essential for understanding the situation and putting the right solutions in place, but with rats and mice continually attempting to push their way indoors, it is critical to concentrate on rodent prevention as well as treatment. In this regard, exclusion and sanitation measures will be vital in preventing future problems once the initial infestation has been dealt with.
Firstly, it is important to take the time to identify all possible rodent entry points. With possible entry points as small as 15mm for rats and less than 10mm for mice and often large buildings to assess, this can certainly be a time-consuming process. Look for direct entry points such as burrows under foundations, open doors, chewed entry points, around drain pipes, in crawl spaces and around utility entry points (electricity, water, gas, air conditioning). Also consider assisted entry points, where vertical wires, pipes and tree limbs have allowed access to thebuilding.
All entry points then need to be sealed. For holes in walls, gaps around utility entrance points and gaps around doors and windows, suitable rodent-proof fillers need to be used. For elements that can be used by rodents to access the building, such as vegetation, wires and drainpipes, these need to be trimmed back (trees) or protected (drainpipes) to prevent rodents climbing the element.
For doorways, self-closing devices should be used on frequently used doors. Vinyl, rubber or bristle sweep seals need be installed under large doors to eliminate gaps.
Secondly, clean up potential rodent harbourages. Maintaining a one-metre clear zone around the perimeter of buildings is a great starting point – and remove all weeds and clutter. Clear away piles of wood, pallets and junk from the property.
The third element for making the property less attractive to rodents is to reduce sources of food and water. Ensure garbage is place in hard, well-sealed garbage containers, and that food is stored is in hard, sealed containers or rodent-proof rooms. Ensure any food spills are cleaned up immediately.
Once you have implemented your exclusion and sanitation program, efforts by rodents to return to their old feeding grounds will be strongest a week or two after the building has been sealed up, so look for new holes and tunnels during this period and treat as appropriate.
Exclusion and sanitation programs can certainly be involved and time consuming on large commercial sites, but in the long run they can save time, money and your reputation.