How Cute Ferret-Like Animals Cause Germany $65 Million In Car Damages Each Year

A Marten getting ready to ruin this car’s rubber and plastic bits. Image: Abenteuer Auto/YouTube (screengrab)

Don’t be fooled by that cute little fluffball in the picture; mention the word “Marder” to any German, and you’ll send shivers down their spine. Marder is the German word for Marten, a little furry animal that crawls into cars’ engine bays and wreaks havoc on coolant hoses, spark plug wires and more, causing tens of millions of euros in damages each year. Tens of millions! Here’s what’s going on.

I recently met up with Jalopnik reader Andreas (TheSafetyEngineer) in Bavaria to wrench on his Mazdaspeed 6. While changing a serpentine belt, I noticed Andreas’s car had a random red cable underhood and that it was making this god-awful noise (listen below). Andreas said the noise was coming from his broken anti-Marten ultrasonic device, and that the red cable was a high voltage line meant to shock the little pests.


I thought this seemed a little random and odd to install into a sports sedan, but Andreas told me this was a big, potentially-expensive problem in Germany. Then I did some research, and holy crap was he right.

Marten Damage Is A Huge Deal In Germany

Photo: GDV

I called up ADAC, basically Germany’s superpowered version of AAA, and asked for some info on this whole “Marder” issue. The woman over the phone sent me to the Association of German Insurers, GDV, and I found the plot you see above.

This column plot shows the number of claims related to Marten damage in thousands (on the left), and the number of millions of euros in damage those claims amount to (on the right). The takeaway is that between 2010 and 2014, these pesky Martens caused over 300 million euro in damage (or about $330 million) through 1.1 million insurance claims.


$330 million over a span of only five years!


To put that into perspective, check out the table above. In 2012, Marten damage was the third most frequent insurance claim in all of Germany, with 233,000 cases amounting to 64 million euro in damages, according to GDV— bested only by cracked windshields and wildlife-related accidents.

And if you’re still not convinced, here’s a plot showing the number of times ADAC (again, Germany’s ‘AAA’) had to send roadside assistance out to help some poor motorist whose coolant hoses and spark plug wires had been torn apart by the little Martens:


Yes, that’s over 14,000 roadside incidents every year since 1998, and those usually only happen if the car doesn’t run or drive. Many more incidents are overlooked and ADAC never called.

It’s such a big issue that in Stuttgart alone, one third of all parked cars were found to have some trace of Marten infiltration, a finding GDV attributes to the Nature Conservatory Nabu.


So yeah, this Marten damage (Marderschaeden) issue is a big deal.

They Can Totally Destroy Your Car

Martens love to bite through coolant hoses, rubber axle and steering boots, and wiring. Photo: GDV

Martens love to chew on rubber and plastic. The most common victims of Martens’ ridiculously sharp teeth are spark plug wires, coolant hoses, wiper fluid hoses, rubber CV axle boots, rubber steering rack bellows, wiring insulation and underhood sound deadening material.

Though ADAC says they haven’t seen any cases of brake hoses or tires being chewed up by the animals (thank god), the parts Martens do chew on can completely ruin a car.


Once a steering bellow (shown in the picture below) or CV axle boot gets a hole in it from a Marten bite, water and grime will get into the joint, compromising the lubrication and destroying the CV axle or inner tie-rod end in short order, and leading to very costly repairs.

The steering bellow (rubber boot) you see in the image above is highly vulnerable to Marten bites, which is why this one has a high-voltage cable going to it to shock the little pests (the high-voltage cable is hard to see in this image).

A hole in a coolant hose can cause a car to overheat, crack a cylinder head, blow a head gasket, or even seize—all potentially catastrophic for a car.

And driving with a chewed-up ignition wire, ADAC says, can lead to a misfiring engine, meaning unburned fuel will enter the exhaust stream and lead to destruction of catalytic converters, and those things aren’t cheap to replace.


Plus, electric and hybrid cars, with their copious wires, are also highly vulnerable to costly damage, and they can catch fire if Martens chew off high-voltage insulation.

The worst part of all this is that some insurance plans only cover replacement of the chewed-on plastic or rubber part, and not the resulting damage. In other words, some insurance will only cover the coolant hose, not the blown head gasket; the spark plug wire, but not the blown catalytic converter.


So clearly, those huge $65 million-a-year insurance repair costs are conservative, and don’t account for people who don’t file claims, or whose insurance doesn’t cover potentially disastrous resulting damages.

Why Do They Do It?

Photo: Peter G W Jones/Flickr

ADAC says martens used to be extinct in Germany back in the 1950s, as people hunted their precious furs. But now the marten population has swelled to the point where they’re not only in southern German like they were before, but also up north. Not to mention, they’ve adapted to cities, meaning this marten problem is truly Germany-wide.

Martens invade engine bays because they are drawn in by the warmth and safety of the enclosed engine bay, or by the smell of urine and feces from other martens. Once inside, they bite into hoses and wires to make space for themselves or just for fun, ADAC says. They also urinate and leave bite marks in plastic and rubber as a way to mark their territory.


It gets worst in early summer, when the little critters start mating — a time when they’re highly territorial, and very likely to mark their space with torn cables and hoses.

There’s No Really Good Way To Stop Them

There’s actually a wildlife biologist name Hans-Heinrich Krüger (the man with the most German name ever) who has done research for car manufactures and suppliers for over a decade to figure out how to prevent Marten damage, GDV reports.


He works for a place called the Otter Centre, and he’s been testing all sorts of methods to keep cars safe from martens, including use of hard plastic conduits to protect wires and hoses, closing off the engine bay to keep the animals out, using an ultrasonic sound-wave device to annoy the animals, and electroshock.

Other methods to protect cars against these critters, mentioned in the video above, include using wire mesh under the engine bay—martens hate walking on an unstable floor—and cleaning the engine bay of marten feces so other martens aren’t drawn by the smell


All of these remedies work to varying degrees, GDV says, but none of them works all the time. Martens get used to the ultrasonic sound (which tends to be damped by the various parts in the engine bay), and they find ways to get past closures.

There are also ridiculous remedies that Germans have thought of, like sprinkling dog hair, urine cakes, garlic cloves, mothballs and even human urine on the engine. The problem is, Krüger and ADAC agree, Martens get used to smells very quickly, and these remedies just don’t work.


In the end, it seems Germany’s got a major problem with no perfect solution. As GDV puts it:

Every driver has to expect that one morning the engine can not be started because of a Marten damage. Annoying but effective remedies against the martens do not exist. The only thing that really helps: a decent insurance.


But that quote is coming from the Association of German Insurers, so they would say that.

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About the author

David Tracy

Sr. Technical Editor, Jalopnik. Always interested in hearing from auto engineers—email me. Cars: Willys CJ-2A ('48), Jeep J10 ('85), Jeep Cherokee ('79, '91, '92, '00), Jeep Grand Cherokee 5spd ('94).