You think it’s bad when a squirrel runs in front of your car? Try when they hijack the whole engine. Chris Persic was already dealing with his two-month-old truck shaking like a washing machine on spin cycle when his wife, Holly, called about a burning smell around her Kia. Turns out, the squirrels in Pittsburgh weren’t just stealing bird seed—they were laying siege to car engines. And as Chris soon discovered, these squirrels weren’t just stocking up for winter—they were building a fortress under the hood.

It all started on a rainy Monday when Holly noticed something off with her 3-year-old Kia Sorento. The car was making weird sounds, and a burnt, nutty odor filled the air. “My wife called me from Northland Library and said her car smelled like it was burning, and was making a weird sound,” Chris shared on Facebook. Following his advice, she popped the hood—and found a stash that would make any squirrel proud. Over 200 walnuts and piles of dead grass had been tucked away by the critters, creating a five-star winter retreat right in her engine bay.

Chris, whose truck was already in the shop for what he later suspected was squirrel-induced damage, got a rental car and rushed over to help Holly clean up the mess. It was a long time just to clear out the top layer of debris. “It took almost an hour, and we were able to clean it enough to take it to Tevis Auto Service… to check it out,” Chris said. But when the mechanic lifted Holly’s car, even more nuts came tumbling out, filling another half a trash can. These squirrels weren’t just prepping for winter—they were automotive engineers of the wild.

Unfortunately, Chris’s truck wasn’t spared either. As he posted, “My truck may have had a squirrel chew through/pull out a fuel injector hose.” After getting towed with only 4,000 miles on the odometer, the mechanics discovered more chewed wires—squirrels had turned Chris’s truck into a rodent smorgasbord. The damage “Was absolutely nuts… no pun intended,” he quipped.

Both cars were casualties in a rodent rebellion, and the Persics quickly realized their black walnut tree was the root of the problem. Walnuts had been falling for weeks, denting their hoods and disappearing mysteriously. “Funny thing is I was thinking that for how massive the tree is, and how many walnuts have fallen (and how many dents our vehicle received), there really aren’t many on the ground,” Chris told CBS News. And the answer to this little mystery was one the couple never suspected.

Mechanics told Chris that it was lucky Holly’s car hadn’t caught fire, as some of the walnuts had begun roasting from the engine’s heat. The grass stored under the hood was still damp from the rain, which likely prevented a bigger disaster. “Hibernation prep level: expert,” Chris joked later.

After the ordeal, Chris posted a public service announcement: “Rodents and vehicles do not mix… Long story short, if you park outside, do yourself a favor and check under the hood every once in a while.” It’s advice we could all take to heart—especially if you live near a walnut tree or in squirrel territory. These little guys had turned the Persic family’s cars into their personal food banks.

So the moral of the story? If you live near a walnut tree, keep your garage clean, your hood popped, and your wits sharp—because somewhere out there, a team of squirrels is working harder than your mechanic. Just pray they don’t come for your car next.

Learn how to avoid the same mess in your car in the video below: