Pack rats are attracted to any area that provides opportunities for safe harborage. An ideal harborage is accessible to the pack rat, but not to its many predators including bobcats, owls, snakes and coyotes.
A vehicle engine compartment is close to perfect. Additionally, the sound proofing insulation under the hood provides excellent nest-making material and engine wires are just right for the chewing necessary to maintain sharp teeth.
Many newer cars have engine covers and shrouds that provide hiding places even when the hood is open. Pack rats will also nest above the gas tank and can even get into the air filter compartment.
If you live in an area where there are pack rats there is always a chance that pack rats may do damage to your vehicle. Pack rats even get into garages. There are many things you can do to reduce the risk, in many cases to almost zero.
#1 No pack rat nests nearby! Inspect the general area for nearby pack rat nests. A single female may be responsible for as many as 20 young a year, all who need to find new homes (like your vehicle) as they mature. Removing nearby nests can significantly reduce the risk of attack. Before removing a nest, the resident rats should be trapped. A homeless rat will seek a nearby alternative shelter-most likely your car.
• A Rat-Proof Garage. A pack rat only needs an opening the size of a nickel to enter a garage. They are excellent climbers and can enter high or low. A poorly sealed garage is worse than parking outside, since rats are attracted to an area they can enter, but larger predators cannot.
• Open Space. If a rat-proof garage is not available, the vehicle should be parked in the most open area possible, ideally with at least five to ten feet of totally clear space on all four sides with no trees or other cover above the vehicle.
• No Stored Items Close By. If the vehicle must be parked in a carport, there should be no other items stored in the carport including boxes, yard tools, and trash containers. Any additional cover from stored items makes the area more attractive.
• Vegetation Trimmed. Keep all vegetation in the immediate area well trimmed to eliminate as much cover as possible. You should be able to clearly see under and behind all bushes and other plants anywhere near the vehicle. Avoid using rock borders rats can hide next to.
• Hood Open. For many vehicles, leaving the hood open takes away the sense of enclosure and protection that the rat is seeking. If you choose to leave the hood open, be sure to disconnect any internal engine compartment lights to avoid a dead battery in the morning. Also, secure the hood with some type of strap if high winds are a possibility. Leaving the hood open does not work as well on newer vehicles with engine covers and shrouds that still offer plenty of hiding areas.
• Light. A utility light hanging from above with an open hood works best. Be sure to use a yellow "bug" bulb to minimize flying insects. A light under the car may help, but not as much as light from above. Lights are not effective on newer cars with engine covers and shrouds.
• Be Alert. If you park outside keep your eyes open for rat droppings and pieces of cactus that show up near or under your vehicle. Lift and check under the hood often. Be extra careful when heavy rain or cold weather may cause rats in the area to look for better quarters.
You can park a vehicle outside for years without a problem, but once rats get into a vehicle, there may be constant reoccurring attacks. Pack rats naturally reuse the same nesting sites generation after generation. The rat “marks” your vehicle with a scent, the same way a dog “marks” its territory. This scent will attract other rats to your vehicle.
Steps to Take:
#1 - Catch the Rat! If a rat is currently infesting your vehicle it must be caught before any other steps are taken! A trap is best. Do not use poison. Poison is food and is designed to attract rats. Once a rat eats the poison they do not die for days and have plenty of time to do damage and leave their scent.
#2 - A Thorough Cleaning. You want to remove as much scent of the previous rat as possible
• Soak all urine stains with a 50% solution of pine oil (Pin-Sol®) and then use a high-pressure hose to clean everything off. Pay close attention to hard-to-reach areas. You may need to remove the battery to clean behind and underneath.
• Once the vehicle is clean, the hood should still be left open as a further deterrent for at least three weeks to be sure the scent is completely gone. Even better park in a well sealed garage if possible.
#3 - Prevention.
No matter how well you clean, some scent may remain and your vehicle will be at higher risk than a car that has not had rats in it before. Read and follow the recommendations in the section Best Bets To Prevent Pack Rats From Attacking Your Vehicle
Be diligent and check the car often. If you see any signs of new activity, put out a trap immediately. Once the car has been rat free for 30 days the risk of re-infestation will be less and you can check less often if desired.
There are many products and myths reported on ways to prevent pack rats. Many are supported with anecdotal claims such as "John Doe used this and never saw another rat." Unfortunately there is no easy magical cure and I know of no product that has held up to true scientific testing.
Mr. Pack Rat has thousands of customers. Many have tried everything before they finally called us. Learn from their experience and ours.
• Poison Bait — Poison bait is rat food. If you want to attract birds, you put out bird food. Putting out rat poison attracts rats. They may eat the poison and die or they may collect it for their food stores. All poisons take 5-10 days to work, so even if the rat dies there is still plenty of time to do damage and “mark” your vehicle as an excellent nesting site. In most areas, there are too many rats and they breed too quickly to ever be poisoned to oblivion. See the Problems with Poison page for full details.
• Mini-strobe Lights — There are simply too many hiding places in most cars for these lights to really be effective. Also pack rats adapt quickly. A light in an enclosed area is still a safe enclosed area and the rat will just ignore the light after a short time
• Moth balls — Under NO circumstances should moth balls be used as a pack rat deterrent. They are both hazardous to human health and EPA regulated against use of this type.
• Ultrasonic devices — Rats will nest near, next to and even on top of ultrasonic devices.
• Commercial repellent sprays — Pack rats ignore them.
• Potato flakes — Pack rats will not actually eat the flakes, swell up and die.
• Ivory or Irish Spring soap — The smell does not bother pack rats and if they eat the soap it will not harm them.
• Dryer sheets — The smell does not bother pack rats.
• Predator urine — (bob cat, wolf, cougar, human or otherwise) The smell does not bother pack rats.
• Gum — Pack rats will not eat the gum, choke and die.
• Pepper/chili powder — Pack rats love chili seeds and the powder does not bother them.