Quick answer
Signs of rodent damage include sudden warning lights or odd electrical faults after the car has been parked, chewed insulation or loom tape, droppings, nesting material (leaves, paper, insulation) under the bonnet or in the air filter box, and a burning or unpleasant smell. Rodents shelter in warm engine bays and gnaw to wear down their teeth. Small, visible damage can sometimes be repaired, but damaged looms often need professional repair, and some insurance policies exclude rodent damage, so check your policy.
Is this a DIY job?
- Difficulty: Easy to inspect; Pro to repair most wiring damage
- Time: 15 to 30 minutes to inspect
- Tools: torch, gloves, mask, camera
- Skills: careful looking
Repairing wiring properly means matching wire sizes, staggering joints, sealing against moisture and protecting the loom again. Damaged looms may also carry sensors, airbag or driver-assistance circuits. Most owners leave repairs to an auto electrician.
Step by step
- Don’t keep driving with new, unexplained warnings. If warning lights appear suddenly, the engine runs badly, or you smell burning, park safely and investigate before driving further.
- Open the bonnet and look carefully with a torch. Wear gloves and a mask: droppings and nests can carry disease.
- Look for the tell-tale signs: – chewed insulation, exposed copper or bitten loom tape and conduit – droppings, urine stains, food scraps, nests in corners, on top of the engine or in the air filter box – chewed insulation pads on the underside of the bonnet
- Check the air intake and cabin filter. Rodents often nest in air boxes and the cabin air intake below the windscreen. A blocked or chewed filter can cause smells and poor airflow.
- Photograph everything. Photos help with an insurance claim and a repair quote.
- Check your insurance policy. Some policies exclude damage by rodents or vermin. Ask your insurer before starting repairs.
- Get the wiring repaired. An auto electrician will trace every damaged wire, repair or replace the section, and re-protect the loom. Then any fault codes are read and cleared.
- Clean out nests safely. Wear gloves and a mask. Don’t sweep, vacuum or blow out dry droppings. Spray the nest and droppings with disinfectant or a diluted bleach solution, let it soak for a few minutes, then pick it up with paper towel and seal it in a bag. Wash your hands afterwards.
- Reduce the chance of a return visit. See the prevention list below.
Specs table
Prevention
| What to do | Why |
|---|---|
| Don’t leave food, pet food or rubbish in or near the car | Food attracts rodents |
| Keep the garage or parking area tidy and sealed | Fewer hiding places and entry points |
| Trim branches and vegetation near where the car parks | Reduces access |
| Use baits only in lockable bait stations, or traps | Bait stations keep pets, children and other animals out; follow label directions |
| Start and drive the car regularly | A car that sits for weeks is more inviting |
| Check under the bonnet if the car has been parked for a while | Catch damage early |
| Consider rodent-deterrent tape or mesh over air intakes | Some owners use these; results vary |
Common symptoms after rodent damage
| Symptom | Possible cause |
|---|---|
| Sudden check engine or other warning lights | Sensor wiring chewed |
| Car won’t start or cranks but won’t start | Starting, sensor or fuel pump circuit damaged |
| Lights, wipers or gauges acting oddly | Chewed body or lighting wiring |
| Burning smell | Short circuit, or nest on a hot exhaust |
| Musty smell through the vents | Nest or droppings in the cabin air intake |
What you’ll need
For prevention and inspection:
- rodent deterrent tape
- split loom tube (to protect exposed wiring after repair)
- cabin air filter (if contaminated)
For repair (usually by a professional): automotive wire, solder sleeve connectors, adhesive heat shrink, loom tape.
When to call an auto electrician
- Any chewed wiring, especially in the engine loom, near sensors or near the airbag and driver-assistance wiring.
- Warning lights or running problems after rodent activity.
- Hybrid or EV high-voltage (orange) cables are damaged. Don’t touch them: professional-only.
- There’s a burning smell, melted insulation or signs of a short circuit.
Need an auto electrician? Find local auto electricians and mobile services in your city.
Related questions
Q: Does car insurance cover rat damage? A: It depends on the policy. Some exclude damage by rodents or vermin. Check your product disclosure statement or ask your insurer before repairs start.
Q: Why do rats chew car wiring? A: Rodents gnaw constantly to keep their teeth worn down, and warm, sheltered engine bays are attractive in cooler weather. Food and nesting material nearby make it more likely.
Q: How much does it cost to repair rodent damage? A: It depends on how much wiring is damaged and whether a loom must be replaced. Minor repairs can be modest; extensive damage can cost thousands of dollars or even make a car uneconomical to repair. Get a written quote after inspection.
Q: Do ultrasonic rodent repellers work in cars? A: Results are mixed and there’s limited independent evidence. Removing food, sealing access and regular use of the car are more reliable.
Sources
- The New Daily, “Rats car damage” (April 2021) – rodents seeking warmth in engine bays, gnawing on wiring; example repair cost around $2,000 and a car written off; insurance exclusion example; Brisbane City Council prevention advice; bait stations. https://thenewdaily.com.au/news/queensland/2021/04/23/rats-car-damage (checked October 2026)
- Brisbane City Council, “Rats and mice” – baits and traps; follow label safety instructions; lockable bait stations and traps are safer around children and pets. https://www.brisbane.qld.gov.au/environment-waste/natural-environment/biodiversity-brisbane/wildlife-brisbane/pest-animals-invasive-species/rats-mice (checked October 2026)
- SA Health, “Rats and mice – prevention and control” – remove food and shelter, cut back vegetation, seal entry points; rodents can carry diseases such as leptospirosis. https://www.sahealth.sa.gov.au/wps/wcm/connect/Public+Content/SA+Health+Internet/Conditions/Bites+stings+and+pests/Rats+and+mice+prevention+and+control (checked October 2026)
- NSW Health, “Staying healthy during a mouse plague” – diseases spread by rodent urine and droppings; wear gloves, clean with disinfectant or bleach, wash hands. https://www.health.nsw.gov.au/environment/factsheets/Pages/mouse-plague.aspx (checked October 2026)
- US Centers for Disease Control and Prevention, “How to clean up after rodents” – soak droppings and nests with disinfectant before removal; don’t sweep or vacuum; bag and seal. https://cdc.gov/healthy-pets/rodent-control/clean-up.html (checked October 2026)