How to Know If You Have a Rodent Problem
Rats and mice are nocturnal and naturally cautious, which means you’ll often hear or smell them long before you see one. Knowing what to look for allows you to act quickly — rodent populations double every few weeks, so early detection is crucial.
1. Droppings
Rodent droppings are typically the first and most obvious sign. They are dark, moist when fresh and harden as they age.
- Rat droppings: 15–20mm long, spindle-shaped, often found near food sources, along walls, and in roof voids
- Mouse droppings: Much smaller — 3–6mm — with pointed ends, scattered in large numbers
Focus your inspection around the back of kitchen cabinets, under the sink, in the pantry, and in the roof void.
2. Gnaw Marks
Rats and mice gnaw constantly to keep their teeth from overgrowing. Fresh gnaw marks are pale in colour and lighter than the surrounding material. Look for gnaw marks on:
- Food packaging and containers
- Timber skirting boards and door frames
- Electrical cables (a serious fire hazard)
- Plastic water pipes
- Insulation in the roof void
3. Scratching and Scurrying Sounds
Sounds from the roof void, inside walls or under floorboards — particularly at night — are a strong indicator of rodent activity. Rats produce louder, heavier sounds; mice create lighter scratching and rustling noises. You may also hear gnawing sounds in walls, especially at night.
4. Grease Marks (Rub Marks)
Rodents have poor eyesight and navigate by following established routes along walls and fixed objects. The oil from their fur deposits a dark grease mark along these regular paths. Look for dark smears along the base of walls, around gaps and entry holes.
5. Nesting Material
Rats and mice build nests from shredded soft materials — paper, insulation, fabric, cardboard and plant matter. Nests are typically found in warm, dark, undisturbed areas such as roof voids, wall cavities, inside appliances and behind stored items in the garage.
6. Footprints and Tail Marks
In dusty areas like the roof void or garage, you may be able to spot small footprints or tail drag marks. Sprinkling a thin layer of flour or talc in suspected areas overnight is an effective way to confirm activity.
7. Unusual Pet Behaviour
Cats and dogs often detect rodents long before humans do. If your pet is fixated on a particular wall, cabinet or area, sniffing intensely or pawing at a surface, it may be alerting you to hidden rodent activity.
8. Smell
A large or established rodent infestation produces a distinctive ammonia-like smell from urine. You may also notice a musty odour in confined spaces like roof voids, under sinks or inside wall cavities.
What to Do If You Spot These Signs
If you’ve identified any of these warning signs, act immediately. Rodent populations grow rapidly — a single breeding pair of rats can produce up to 100 offspring per year. Professional rodent control is far more effective than consumer baits and traps, which rarely address the full extent of an infestation.
Pestyologist provides fast, effective rat and mice control across Sydney. Contact us today for an inspection and treatment plan.