Squirrels are to blame for two recent power outages in Penobscot County. Credit: Aislinn Sarnacki / BDN

Editor’s note: This story was originally published in September 2022.

You might think that at some point in their evolutionary process squirrels would have learned not to mess with power lines or electrical facilities.

Unfortunately for both the squirrels and those who rely on power utilities, that is not the case.

Falling trees or branches are the number one cause of power outages in Maine but squirrels are a close second. Over the past two weeks, power outages caused by squirrels in Brewer and Bangor left thousands without electricity.

Squirrel-related power disruptions are not unusual this time of year, and there are likely more to come.

“It’s fall and the squirrels are stocking up on food for winter and out and about,” said Marissa Minor, a spokesperson for Versant Power. “Squirrels are common problems for utilities, and squirrels have certainly been a prevalent issue for us this year.”

Just why squirrels think it’s a good idea to mess with high-voltage electrical wires or equipment is not fully understood. Squirrels do like to chew and a wire could easily be mistaken for a tree limb, especially if those wires are running near actual trees.

Squirrels also like enclosed spaces and a protected nook or cranny at a power substation could look like an ideal nesting place.

Regardless of how the animals get into the electrical infrastructure, they can bring down parts of the grid one of two ways, according to Minor.

“If the squirrel comes into contact with two areas of voltage it creates a fault and that blows fuses,” she said. “The second way is when a grounded object — in this case the squirrel — becomes an electrical conductor, sort of like sticking your finger into a light socket.”

Versant power crews believe it was the latter that caused the two-hour outage in Bangor on Sunday, Minor said.

“It certainly is a nuisance,” she said. “They can get into all kinds of equipment.”

To help defend against squirrel attacks, Minor said Versant has installed special “squirrel guards” in vulnerable areas at their substations. She said crews will continue to install such devices when new areas are identified as possible squirrel targets.

“As the squirrels gear up for winter, we could see more squirrel-related power outages,” Minor said. “We can’t predict them and hopefully the animal protection guards will work.”

In the meantime, Minor did say it could be worse. Squirrels may be the problem in the north, but in the south power disruptions are often caused by snakes slithering into substation areas.

Julia Bayly is a reporter at the Bangor Daily News with a regular bi-weekly column. Julia has been a freelance travel writer/photographer since 2000.