At our latitude, most food pests rely on heated rooms and cannot survive out in the open for long. Thus one may be inclined to forget what is going on outside the company walls. Mice, rats and birds always come in from outside. Problems with certain insects are due to factors outside the company’s environment, which is appealing to the animals.
Vegetation: Plant growth in the surrounding area should be well kept. Bushes and shrubs that can be habitats for rodents and bird flocks should be avoided and grass should always be kept low. A zone of at least 1 m along the base of the buildings should be completely free of vegetation and other conditions that may be tempting shelter for pests. Otherwise pests like woodlice and earwigs accumulate at the base with the risk that they eventually wander inside buildings and end up in the products. If it is necessary to treat with poison to keep crawling insects out of the business, it can also be done in such a barren zone.
Loading ramps must be free of holes and crevices in which different residues can accumulate. They should not be the repository of returned goods, which might just include complaints with pests.
Railway tracks leading onto the premises must be free of weeds and debris.
Waste sites must be easy to clean and supplied with a sufficient number of suitable containers, which are emptied and cleaned effectively and frequently.
Roofs and gutters should be clean and free of bird nests.
Outdoor storage areas: Packaging, pallets, etc., which at times are stored outdoors should be raised at least 0.5 m above the ground. This will reduce the risk of them being used as hiding places for pests of various kinds that can then be brought inside the building.
Light attract many insects. Bright lights outdoors on or nearby the buildings can attract insects in large numbers at night. Should there be lights at night then it should not be placed near places where there may be a risk that the insects that are drawn to it can penetrate the building. Pests that are attracted to light have no purpose in food storage. This may explain the findings of midges, night crawlers and random moths in food.
Premises: All kinds of hiding places, from fine cracks to larger cavities are unfortunate. They allow the accumulation of things that animals can live on, and they can lead to large populations evolving without you noticing it. Finally, such places give pests some protection from the extermination.
There are some general guidelines that should be followed when it comes to the design of buildings.
All internal building structures must be free of cavities, crevices and cracks. All columns or beams constructed of steel or the like must therefore be completely closed.
Walls and ceilings must be of solid construction. In many false ceilings, there are built-in lighting fixtures that provide heat, and this makes the cavity more appealing to pests. Behind wall tiles that are only configured with a dollop of mortar is a maze of hallways in which cockroaches like to live, and where they are very difficult to control.
Shelves and cupboards should either join completely dust-sealed to the floor or be so much free of it that you can clean under them. All electrical installations, lighting fixtures, cables, cable trays, etc., should be placed at least 2 cm from the supporting element.
Cavities. When it is not possible, due to lack of space, to make cavities reasonably large and easy to clean, for example behind a bakery oven, the solution can be to fill the cavity with a material that does not leave room for pests, or which directly kills them. Diatomatic earth is an option. Diatomatic earth kills insects because it destroys their protective layer of wax, so that they will dry out. If kept dry, it retains its effect indefinitely. A filling with compressed mineral wool mats possibly powdered with diatomatic earth or technically pure boric acid, is another option. In machinery and transport routes there are countless places in which residue from production accumulates and populations of pests can be maintained. It should be a requirement for the design that machinery can be easily removed, to make frequent and effective cleaning possible.