Why work from signs?
Most facility pests are nocturnal and live hidden: in structural voids, under machine bases, on cable trays, inside stored goods. By the time a live individual is seen in daylight, the population is already substantial. In practice, this is why we identify the species from its signs.
This page describes the method – what each finding means, and how much it reveals about the extent of an infestation. The detailed, species-by-species description, with typical hiding places and the effective treatment, is on the Pests pages.
What to look for
Droppings. The most revealing finding, since size and shape are species-specific and quantity indicates the extent of the infestation. In rodents, rice-grain-sized droppings with pointed ends indicate a mouse, while larger, blunt-ended droppings are characteristic of the rat. In the cockroach, tiny grains resembling ground pepper appear along cracks and crevices.
Gnaw marks. On packaging, cables, door frames – these point to rodents. Gnawed cable insulation is also a fire hazard.
Shed skins. Insect nymphs moult several times as they develop, and the shed skins accumulate right next to the hiding place. For the bed bug, this is the most reliable early sign.
Webbing and clumping. Clumps of stuck-together grain or produce inside stored goods point to stored-product moths; a small, round exit hole in a grain kernel points to weevils.
Rub marks. Along regularly used routes, body grease leaves a dark, shiny smear low on the wall. This is what reveals the route.
Chewed paper and wallpaper. Irregular-edged, yellowish-stained patches on documents, book bindings or packaging – in a humid room – point to silverfish – and to a problem with the room’s ventilation.
Trails. Ants travel along a fixed trail; the direction of the trail leads to the nest.
A constant entry and exit point. Continuous traffic observed at a gap or under the eaves points to a wasp nest – even without opening up the structure.
What a finding reveals about the extent
A single sighting on its own says little. In practice, two things matter:
Where. A finding in a sensitive zone – a food-contact surface, the packaging area, the finished goods warehouse – is an order of magnitude more serious than the same finding on the perimeter.
Where it’s heading. In a facility, the most reliable signal is not a visual sighting but the trend in catch data from the monitoring points. A steadily rising catch is a signal even while the absolute number is still low – and an audit asks for exactly this data as evidence that the programme works.
Not sure about a finding?
Send us a photo of the finding through any of our contact channels. Based on the preliminary identification, we arrive on site already equipped with the right technology and product, which makes the intervention shorter.