Squirrels hate Christmas. Or maybe squirrels love Christmas?

Hard to tell. Either way, they’re messing with it across the continent.

In Seattle this month, homeowner Margaret Rican filmed a squirrel’s repeated theft of her Christmas light bulbs. One by one, a rodent she dubbed the “Bulb Bandit” made off with dozens of them a day. “He has stolen 150 in 24 hours, carefully and precisely chewing through the wires to steal the bulb and bury them around the neighborhood,” Rican wrote on YouTube. “He’s the hardest-working rodent we’ve ever seen.”

This week, the Boston Globe reported that a band of squirrel outlaws had repeatedly caused outages of the holiday lights adorning 60 trees on Boston Common. A city official said he had been told the rodents like the taste of copper. A city contractor who maintains the lights referred to the local squirrels as “more and more aggressive.” He said his company was turning to an organic product called “Critter Ridder” to keep the squirrels from killing the city’s holiday vibe.

And on Wednesday, the Canadian Broadcasting Co. revealed that squirrels have been destroying the lights that cast a glow on a park called Mel Lastman Square in Toronto. A city council member, John Filion, told the Canadian Broadcasting Corp. that officials were looking into “squirrel-proof lights” to brighten the park and its ice-skating rink.

“I believe it totally has to do with one or more squirrels who perhaps don’t like Christmas,” Filion said.

Mikel Delgado does not concur. Delgado, a doctoral candidate at the University of California at Berkeley who studies squirrel caching, said she does not think squirrels “have a vendetta against Christian holidays.”

Instead, she said, it’s likely that bulb-stealing squirrels are simply mistaking their booty for nuts. It’s a busy, pre-winter food storage time for squirrels, and Christmas lights are vaguely shaped like acorns, so “there’s something about the light bulbs that is similar enough to nuts that it’s probably worth taking the chance,” she said. Also, nuts fall during autumn like manna from squirrel heaven, so the little fellows are not super hungry and they probably bury their treasures without testing for edibility, she said.

“If there were Christmas lights in summer, the squirrels would probably figure it out pretty quickly,” she said, though she said it was puzzling that they do not seem to realize that light bulbs do not smell like food.

As for those wires: Rodents love chewing wires (in car engines, too). Their teeth grow constantly, so it’s their instinct to gnaw and keep the chompers trimmed. “A wire is not that different from a thin branch or twig they might chew on,” said Delgado, who added that she’d never heard that squirrels have a taste for copper.

This is hardly the first holiday season that squirrels have sought to stymie. Last year, the Norwalk, Conn., city hall’s tree lights were hit with attacks by bushy-tailed insurgents. In 2014, the Cincinnati Zoo’s Festival of Lights was regularly darkened by strand-chewing squirrels. Zoo workers doused the worst-hit spots in hot sauce, but, the Cincinnati Enquirer reported at the time, it “seems the squirrels may like their cords with a little hot sauce.”

But as is well known, squirrels harbor far grander ambitions: They want to take our power.

Squirrels have successfully knocked out parts of the world’s power grids at least 854 times since 1987, according to the monitoring website Cyber Squirrel 1. The site’s Twitter account, which is written by an unnamed “Cyber Squirrel” operative and chronicles animals’ most recent “unclassified ops” against electrical systems, said this week that Christmas light strands are appealing not because they contain copper, but because of the “soy-based plastics covering the copper.”

Read more: