Assess the rat activity:
- Inspect your engine compartment regularly for signs of rats (droppings, chewed wires, gnawed plastic, nesting materials).
- Determine if activity is better/worse during certain seasons or in different parking spots.
- Try not to park near shrubs, wood piles, or other areas that may harbor rats.
- Similarly, avoid parking near food sources such as fruiting trees and vegetable gardens.
- If you can leave your hood up overnight, it denies the rodents a safe, hidden space.
- Park in a garage and keep the door closed.
- Don’t leave food, or food wrappers in the car. The scent of food may draw rats to your auto.
- Ask your mechanic to bring to your attention any evidence of rat activity.
Drive them away:
- Use a chemical repellent in lieu of rat poison (Pro-PELL, Fresh Cab, Rataway, peppermint oil, cayenne pepper). Be prepared to reapply every few days.
- Install lights in the engine compartment. Vekibee Ultrasonic Rodent Repellent for Car Engines and Loraffe Under Hood Ultrasonic Rodent Repellent are two low-cost options.
- Some people claim that mothballs, dryer sheets, and Irish Spring Soap can act as a deterrent when placed in the engine compartment. These may have limited utility in deterring rats, it may be worth a try.
- Ulta-sonic devices have also been used. Again, some people claim great success while others see no impact on rat visits.
- Some car makers have begun using soy-based materials in lieu of plastic. These soy-based materials may attract rats. Talk to your mechanic about the possibility of covering wires with rodent resistant tape. The tape is infused with metal or capsaicin (HONDA OEM 4019-2317).
Use non-poison baited traps:
- Avoid using rodenticide, sticky traps, or live traps.
- Baited electric zappers (Raticator, Rat Zapper) can be placed in 5-gallon shop buckets laid on their sides near the front tires. Keep buckets from moving by bracing with a brick (rats often enter the engine compartment through the wheel well).
- Enclosed snap traps and Roadblock Bio-Repellent can be place near the front tires, but do not need to be placed in buckets.
- Place traps in the evening and remove them from use in the morning to protect other animals.
- Dead animals should be wrapped in newspaper and disposed of in the trash container.
Consumer Reports (2023). How to protect your car from rodents
Rat King Dave How to prevent rats from eating your car wires.