Signs You Have a Rat Infestation

Droppings Are Usually the First Clue

Rat droppings are dark, roughly the size of a grain of rice or larger, and tend to cluster near skirting boards, in cupboards, or scattered across loft insulation. Fresh droppings are soft and dark; older ones dry out and turn grey. Finding a cluster rather than a single dropping usually means an active nest nearby, not just a rat passing through.

Gnaw Marks and Structural Damage

Rats gnaw constantly to keep their front teeth from overgrowing, and they're not fussy about what they chew through. Look for gnaw marks on skirting boards, door frames, food packaging, and especially electrical cables, since chewed wiring is a genuine fire risk, not just a repair bill. Gnawed pipework is another common sign, sometimes only noticed once a leak or damp patch appears behind a wall.

Noise, Smell and Movement

Scratching or scurrying sounds in the loft or wall cavities, especially at night when rats are most active, are one of the more obvious signs once numbers build up. A stale, musty, almost ammonia-like smell in enclosed spaces is another, caused by a build-up of urine and droppings in one spot over time.

Greasy smear marks along skirting boards or beams are worth checking for too. Rats have poor eyesight and tend to travel the same routes along walls, leaving a dark, slightly greasy trail behind from their fur over repeated trips.

Why It's Worth Acting Early

Rats breed quickly, and an infestation that looks manageable when first spotted is often bigger by the time it's treated. Beyond the practical damage, rats can carry leptospirosis (Weil's disease) and salmonella, both genuine public health risks tied to contact with contaminated water, surfaces or food. The earlier a survey is done, the smaller and cheaper the job tends to be.