Electrical Fire Risk — The Most Serious Rodent Damage
Rodents gnaw constantly to wear down teeth that grow continuously throughout their lives. Electrical wiring in wall voids, attics, and behind appliances is a primary gnawing target. Stripped wiring insulation in wall voids creates arc fault conditions that can ignite wall materials. An estimated 20–25% of unexplained structure fires in the US are attributed to rodent damage to electrical systems. This risk alone justifies treating any known rodent infestation promptly.
The Full Damage Inventory
- Electrical wiring — Gnawed insulation on wiring in wall voids, attic spaces, under appliances, and in the engine compartments of vehicles parked in infested garages. Arc faults from damaged wiring are a documented fire risk. Inspect wiring accessible in attic and crawlspace for evidence of gnawing.
- HVAC and appliance components — Mice nest in the insulated cavities of refrigerators, dishwashers, ovens, and HVAC air handlers. Gnawing on plastic components, wiring harnesses, and insulation inside appliances causes premature failure and can void warranties. Refrigerator fires from mouse-gnawed compressor wiring are documented.
- Pipe insulation and PEX tubing — Foam pipe insulation is a favored nesting material. Norway rats gnaw PEX plastic water supply tubing, causing leaks inside walls that may go undetected for weeks. The combination of moisture and rodent activity accelerates wood rot in affected wall cavities.
- Attic and wall insulation — Blown cellulose and fiberglass batts in attics become nesting material and are compressed, tunneled through, and contaminated with urine and droppings over time. An established multi-year infestation may require partial insulation replacement after the rodent problem is resolved.
- HVAC ductwork — Flexible plastic ductwork in crawlspaces is gnawed through by both mice and rats, creating air leaks that reduce HVAC efficiency and introduce rodent odor and particulate into the conditioned air supply.
D&D Pest Control provides rodent inspection, trapping, and exclusion throughout Franklin County and rural Missouri — visit ddpestcontrolmo.com.