7 Signs of Rats in Your Christchurch Home (and What to Do Next)
Rodents · 2026-03-14
Rats rarely announce themselves politely. By the time most Christchurch homeowners are sure they have rats, the animals have usually been established for weeks — running the same night-time routes through the ceiling, subfloor or wall voids, and leaving evidence that is easy to read once you know what to look for. Here are the seven signs we take most seriously, in roughly the order you will notice them, plus what each one tells you about the size and stage of the problem.
1. Scratching, scurrying or thumping after dark
This is the classic first sign. Rats are nocturnal, so noises start at dusk and run through the night: scratching along ceiling gib, scurrying across the top of wall framing, and — with Norway rats — a heavier thumping as a half-kilo animal moves through the subfloor. Mice make lighter, quicker sounds, usually earlier in the evening. If the noise is loud enough to wake you, think rats rather than mice, and think established runs rather than a single explorer. Take note of where the sound is: ceiling points to ship rats using the roof void; underfloor points to Norway rats; walls can be either, travelling between the two.
2. Droppings where food is stored — or travelled past
Rat droppings are 12 to 18 millimetres long, capsule-shaped with blunt ends, and usually found in clusters along runs: inside the pantry, under the sink, along the back of bench cupboards, in the hot-water cupboard, and in the garage near pet food or bird seed. Fresh droppings are dark and slightly soft; old ones dry pale and crumbly. A few scattered droppings can mean a recent explorer. Dozens in regular lines along a skirting board mean a used highway — and highways mean residents, not visitors. Clean droppings up with gloves and disinfectant rather than dry sweeping, which can aerosolise contaminants.
3. Gnaw marks on wood, plastic, packaging and cable
Rat teeth grow continuously, so rats gnaw constantly to wear them down — and they can chew through wood, plastic, plasterboard, aluminium and even light-gauge steel mesh. Check the bottoms of pantry doors, the corners of plastic rubbish and compost bins, irrigation pipe, and any food packaging in open storage. Gnaw marks on electrical cable are the urgent ones: chewed wiring in wall voids and ceiling spaces is a genuine fire risk, and it is also one of the most expensive consequences of leaving rats alone. If you find fresh pale gnawing on cable insulation, treat the job as priority.
4. Greasy smear marks along walls, beams and pipes
Rats have poor eyesight and navigate largely by touch and scent, running the same memorised routes night after night with their bodies brushing the same surfaces. Over time the oil and dirt in their fur builds into dark smears along skirting boards, the bottom of fences, subfloor bearers, pipes and beams. Smears are one of the most under-read signs in a house: they tell you not just that rats are present, but exactly which routes they use — which is precisely the information needed to place traps and stations where they will actually work.
5. Nests, burrows and food caches
Outside, look for burrow entrances 6 to 9 centimetres across under sheds, along fence lines, in compost heaps and under dense ground cover — often with smooth, worn soil at the lip and a faint musky smell. Inside, rats shred insulation, paper, fabric and plant matter into nests tucked into undisturbed voids: the back of the garage, under batts in the ceiling, inside stored furniture. You may also find caches — stockpiles of pet food, nuts, fruit or bird seed hidden in a corner of the shed or subfloor. Burrows plus caches mean a breeding population, not a passing animal.
6. Pet behaviour changes and kitchen odours
Dogs and cats often notice rats before people do: a dog suddenly obsessed with one corner of the deck, staring at the same ceiling spot each evening, or a cat bringing in more kills than usual. Indoors, an established infestation produces a musky, ammonia-like odour — strongest in enclosed spaces like the hot-water cupboard or under the house — from urine trails and nesting material. If guests notice a smell you have gone nose-blind to, believe them.
7. Fruit, vegetables and rubbish showing neat gnawing
Half-eaten mandarins and feijoas under the tree with clean-edged gnaw marks, chewed-through rubbish bags, and bird feeders emptied overnight all point to rats working the section. Autumn is peak season: ripening fruit, cooling nights and seed heads push rodents toward houses, and a section that feeds them becomes a section they nest in. Fallen fruit left on the ground is effectively a rat feeder — picking it up daily in autumn does more than most people expect.
What to do next — in this order
First, confirm: torch-check the pantry kickboards, hot-water cupboard, subfloor hatch and ceiling hatch for droppings and smears, and listen for two or three nights to map where the noise is. Second, deny food: seal dry goods and pet food in hard containers, pick up fallen fruit, secure rubbish and compost, and clear the crumbs-and-crushed-biscuit layer behind fixed appliances. Third, cut access where you safely can — door sweeps, mesh over obvious vent holes, sealant around pipe entries — while leaving the harder exclusion for the inspection visit. Fourth, get the knockdown done properly: traps and secured stations placed exactly on the mapped runs, out of reach of children and pets, followed by a return check to confirm the runs are quiet. Skip straight to poison scattered in the ceiling and you risk dead rodents in irretrievable voids and a colony that simply re-routes. If you are in Redwood or anywhere across Christchurch and the signs above sound familiar, start with our rat control page, which walks through how identification, knockdown, exclusion and follow-up fit together — or find us through the contact page and we will take it from there.
