1. Park in a garage
The easiest way to reduce the chances of a critter building a nest beside your engine is to park in a garage. Unless you have rodent problems in the garage (which is a separate issue), the chances of a critter from outdoors crawling into your vehicle are much lower than if you parked on the street. This is especially true on cold nights, when critters are often looking for a warm place to spend the night. The warmest place available is often the engine compartment of a recently driven vehicle.
2. Trap the rodents
If you must park outdoors, use common mouse traps to trap critters that are crawling around your vehicle when you're asleep. Place these mouse traps in your engine compartment and on the floor of your car. You can use various types of bait to attract the animal, then just nab the culprits in the morning. Spending a few bucks on mouse traps will be much cheaper than replacing a wiring harness.
3. Use dryer sheets and mothballs
Dryer sheets and mothballs are also commonly used to prevent rodents from nesting in your ride. Most people prefer dryer sheets because they smell better, but either solution will work to keep critters at bay. Like the traps, these items should be placed in various parts of your vehicle to prevent both engine compartment and interior damage.
4. Tape your tailpipe
The last thing you want is a dead rodent stuck in your car's exhaust system. The solution to this is to seal your tail pipe with masking tape when you aren't driving it. This is particularly recommended for cars that aren't used frequently. If you start driving around with a dead mouse in your tailpipe, you can be in for an unpleasant and expensive surprise.
Stan Markuze is the founder of PartMyRide.com, the online marketplace for used original auto parts.