Rodents are a winter problem in a lot of homes—especially once the nights get colder and roof spaces and sheds feel like a safe, warm place to hide. The part many homeowners don’t realise: rats and mice can chew cable insulation. If that happens, it can create a fault condition that leads to random tripping, flickering, or (in the worst case) overheating and fire risk.
Why rodents show up in winter (and why wiring becomes a target)
In winter, rodents look for three things: warmth, shelter, and food. Roof cavities, wall spaces, and sheds tick all three boxes. Once inside, they’ll often gnaw on materials to make pathways or nesting space—and cable insulation can be caught up in that.
Warmer roof and wall cavities during cold nights
Stored items and insulation creating hidden runways
Pet food, compost, or general food smells attracting pests
Quiet spaces (sheds/garages) with minimal disturbance
Warning signs to take seriously
Sometimes you’ll hear rodents first. Other times, the electrical symptoms show up before anyone realises there’s a pest problem. The key is to treat unexplained electrical changes as a reason to investigate—especially if they appear alongside signs of rodents.
Scratching noises in ceilings/walls, especially at night
Droppings or nesting material in roof space, shed corners, or near the switchboard area
Unexplained tripping (especially if it starts happening suddenly)
Flickering lights or intermittent power in one area of the home
Burning or “hot plastic” smells (treat as urgent)
Why chewed wiring can become a fire hazard (and what to do)
Cable insulation is there for a reason: it keeps the conductive parts safely separated and protected. If insulation is damaged, it can lead to arcing, short circuits, or overheating—sometimes hidden in roof cavities where it’s hard to notice until it becomes serious.
Don’t ignore repeated tripping. Avoid repeatedly resetting a breaker/safety switch if it keeps going off.
Stop and call if you notice burning smells, buzzing/crackling, or heat at outlets/switches.
Don’t enter roof spaces to inspect wiring yourself—roof cavities can be hazardous and you may not see the real fault source.
Address the pest problem in parallel (trapping/professional pest control) so damage doesn’t reoccur.
Think you’ve got rodent damage to wiring? Harkness Electrical can inspect fault symptoms, test circuits, and identify any damaged cabling or connections—then recommend the safest repair so a hidden winter problem doesn’t turn into an urgent outage or fire risk.
