Why think in layers?
A point network is not a collection of devices but a series of defensive lines. The goal is for a rodent to be caught at the outermost line possible, and for the catch data to reveal on which line pressure is rising – because that shows where intervention is needed.
Three layers build on one another:
1. Outer perimeter protection
Along the property boundary, to assess incoming pressure. This layer shows whether the problem is arriving from outside, and from which direction. It is especially important where the property borders agricultural land, a waterway, a waste facility or a railway.
2. Building edge
Along the walls, near entrances and exits, doors, and cable and pipe penetrations. Rodents travel along walls, so this edge line reveals the most.
3. Indoor monitoring
In the production, packaging and storage areas. Here the goal is not extermination but early warning. In areas that handle food, we use non-toxic devices – monitoring blocks, mechanical traps or glue-board traps – because a permanent presence of toxic bait indoors is a food-safety risk, and a non-conformity at audit.
Density: what can and can’t be stated
There is no legally fixed spacing that applies universally. What holds true in practice:
- A sparser layout is warranted on the perimeter, a denser one along the building edge.
- Density should increase in high-risk zones – goods-in, around the waste store, warehouse doors.
- Corners, both sides of doors, and penetrations are worth treating as individual points, because these are the actual entry points.
What the auditor asks for is not the spacing in metres but the justification: why this many points, why there. This must be recorded in the programme description.
Numbering and the site plan
Every point gets a number and goes onto the floor plan. A few rules that save a lot of trouble:
- The number must stay fixed. If point 14 is decommissioned, its number should not be given to another location – otherwise the historical data series becomes impossible to interpret.
- The number should also be marked on the device itself, legibly.
- A discrepancy between the plan and reality must be documented when it arises, not the week before the audit.
The most common mistakes
- Too many points, too little data. A dense network is not, on its own, valuable if inspections are rushed. Fewer, well-placed points checked with discipline are worth more.
- Missing the outer layer. With indoor catches but no outdoor data, it is impossible to tell whether the pressure is coming from inside or outside.
- An unchanged network for years. If the facility has been altered, gate traffic has changed, or a new warehouse has been built, the network needs to be reviewed.
- A catch recorded, with no action taken. This is the most common finding at audits: the data exists, but nothing followed from it.
Where to go from here
The data from a point network is only valuable if it is regularly compiled and turned into a trend – which is what our pest monitoring service does. The documentation package built around the network is covered in detail in the HACCP pest control guide, and the differences in emphasis between the standards in the IFS and BRCGS comparison.