It comes in from outside
The Norway rat is a species with a large home range: it roams the area around a site, the sewer network, and neighbouring properties as well. The most important practical lesson follows from this – an individual seen indoors typically doesn’t live there, it comes in from elsewhere.
That’s why bait placed indoors on its own is at best a treatment of symptoms: within a few weeks, another individual arrives along the same route to replace the one that died. The effective answer is perimeter control – a numbered network of monitoring points set up along the boundary of the site, which catches incoming individuals before they get in.
How to recognise it
- Droppings – considerably larger than a mouse’s, and blunt-ended. They accumulate along walls, on walking surfaces and under warehouse shelving.
- Rub marks – along regularly used routes, the grease in the fur leaves a dark, glossy band on the wall, typically low down, where the wall meets the floor. This is the most telling sign: it shows the route.
- Gnaw marks – on packaging, cables, door frames, plastic cable trunking. Gnawed cables are also a fire risk.
- Burrows – along the perimeter, under building foundations, concrete slabs and storage units.
What monitoring adds
In an industrial setting, the most reliable signal is not visual inspection but the trend in catch data from the monitoring points. ARZÉN Kft. records the position of each point on a site plan, keeps a report for every check, and shows from the trend in catch data which section of the perimeter is seeing increasing pest pressure – typically before anyone indoors notices anything.
On an IFS or BRCGS audit, the same dataset is requested as evidence that the programme is working.
In a private home and garden
For a house and garden, we also contract directly with private individuals. The principle is the same, on a smaller scale: sealing entry points, points placed along the perimeter, and eliminating food sources – compost, bird feeders, pet food, open waste bins. Without that, treatment will have to start over.
