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Prevent winter rodent damage

Consider this advice when you’re putting away your machine after harvest.

Andy Castillo

October 31, 2024

4 Min Read
A rat infestation in the engine area
INFESTED: A rat is infested in the engine area of this vehicle. Ken Huening, CEO of CoverSeal, says rodents seek shelter in vehicles. “They nibble. They keep their teeth sharp on stuff that’s readily available,” he says. Photos by CoverSeal

Picture this: The ground is thawing, and the inaugural red-winged blackbird’s song is on the wind, harkening spring’s imminent arrival.

You push open the back door to a gust of cold air and trudge past the shed to the workhorse machine that’s resting where you put it last year.

You pop the hood and check the oil. Everything looks clean. It starts with a sputter on the first turn. It’s all kosher until you check the HVAC system.

With that first blast of air, you’re suddenly breathing in minced rodent feces.

“A lot of nests end up in your airbox. It’s a perfect tunnel inside,” says Ken Huening, a vehicle rodent damage expert and the CEO of CoverSeal, a brand that manufactures tractor covers. “The airbox is probably the most obvious way to know if there’s a problem, because you’ll hear the debris in your fan. You’ll blow ground-up rat poop into your face. The other place they go into is the cubbies in the tire well. You’ll never see them until your ABS connectors get chewed out.”

Rodent damage is a billion-dollar industry worldwide. Huening estimates that car dealerships fix four or five rodent-damaged cars per month, with each repair costing $2,000 or so. While it’s more difficult to quantify how much damage is done annually to agricultural equipment, Huening figures it’s substantial.

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“Tractors are sitting out in fields, next to your barn, and in areas where rodents live. They get infested,” he says, noting CoverSeal’s tractor cover is a best-selling product.

As farm machines become more technically complex, Huening says rodent damage probably will become more of an issue. More electrical components means more wiring that can be chewed.

“They nibble. They keep their teeth sharp on stuff that’s readily available,” he says.

Even under the best circumstances, it’s difficult to stave off rodents. Cats are a tried-and-true solution on every farm, as are traps, but they “don’t necessarily catch them before they get into the vehicle and do damage,” Huening says.

In the care industry, Huening says some people try peppermint oil, putrid feline spray (effective, but disgusting), moth balls and dryer sheets. While these might work for a time, they must be reapplied. Noisemakers simply don’t work.

“Rodents live in the nastiest environments in the world, so these things are not that effective,” he says. “The rodents get used to the noise, and it’s like hearing the garbage trucks in the dump.”

Rat bait isn’t effective either — not because it isn’t lethal — but because the rodents rarely die right away.

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“They don’t always eat them where they are,” Huening says. Rodents often carry food back to safety and consume it there. Additionally, a weakened rodent might crawl back home to take its final breath in your airbox. Or the poisoned body might become easy pickings for an owl. Killing predators compounds the problem.

CoverSeal - CoverSeal’s tractor cover is evenly weighted so that it sticks to the ground, preventing rodents from slipping in beneath it

Vehicle covers, which seal off the machine from top to bottom, are the best solution. That’s because rodents seek out vehicles for safety. Because the tractor doesn’t offer anything edible (unless a sandwich slipped behind the seat during harvest), they’ll move on when their path is blocked. To further dissuade a rodent infestation, you can reduce the population around the vehicle.

Consider the following advice to avoid breathing in rat feces when you first start your machine next season:

Consider the environment. Sheds are optimal, but not always available. Gravel or pavement is also a good option. A grassy field? Not so much. Be aware of areas like wood piles, which provide an easy jumping-off point for escaping rodents.

“Don’t park your vehicle next to a downspout,” Huening says. “Those tend to be elevators for rodents. They tend to go into the downspouts and hide in the eves. The rodents get into the spout, run up the spout and hide in the eves.”

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Open the hood. Rodents shelter in vehicles to get away from predators and raise their young in safety. Opening panels exposes them to the elements and more dangerous circumstances.

“Lift the hood,” Huening says. “If you have an infestation, popping the hood makes them visible to predators.” This could drive them away to a more sheltered area.

Fire it up. During the cold months, start the vehicle occasionally. 

“The rumbling, the noise, drives them out,” Huening says.

He adds a caveat. Once, Huening recalls starting a classic car. He drove out the parent rodents but brought on a more complex conundrum.

“I cooked the babies,” he says.

Use WD-40. Rodents are driven by scent. They track their friends to find safety and avoid danger.

“If you scare one, say a cat jumps out, they dump,” Huening says. “The other rodents can sense that something bad happened there. It’s the same if something is good — they find their way back.”

While not entirely effective, the industrial scent of WD-40 can mask that scent. It’s a simple and inexpensive way to deter rodents. Just be sure to reapply as needed.

Read more about:

Rodent Control

About the Author

Andy Castillo

Andy Castillo started his career in journalism about a decade ago as a television news cameraperson and producer before transitioning to a regional newspaper covering western Massachusetts, where he wrote about local farming.

Between military deployments with the Air Force and the news, he earned an MFA in creative nonfiction writing from Bay Path University, building on the English degree he earned from the University of Massachusetts Amherst. He's a multifaceted journalist with a diverse skill set, having previously worked as an EMT and firefighter, a nightclub photographer, caricaturist, features editor at the Greenfield Recorder and a writer for GoNomad Travel. 

Castillo splits his time between the open road and western Massachusetts with his wife, Brianna, a travel nurse who specializes in pediatric oncology, and their rescue pup, Rio. When not attending farm shows, Castillo enjoys playing music, snowboarding, writing, cooking and restoring their 1920 craftsman bungalow.

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