Squirrels are ruining the lights on the Common Christmas tree

The squirrels on Boston Common are being blamed for cutting off the colorful glow of the holiday season.City of Boston

The Grinches that are trying to ruin Christmas aren’t green this year. They’re gray, with fluffy tails.

Officials from Boston’s Parks and Recreation Department said the festive lights draped on the trees and buildings on Boston Common have been plagued by testy squirrels that have gnawed through the wires and cut off the colorful glow — and the holiday joy for spectators.

“The squirrels have been bad this year,” said Ryan Woods, a spokesman for the department. “We are told they like the taste of copper. They are drawn to it, I guess.”

Each holiday season, the city hires a contractor to string and maintain the lights on the Common. This year, Pembroke-based Your Electrical Solutions, or YES, won the project bid.

Woods said the company placed lights on 60 trees that line the historic public park, as well as on the Earl of Sandwich restaurant, the park’s visitor center, and the building near the Frog Pond. Your Electrical Solutions also put up the lights that decorate the 47-foot white spruce tree that was delivered to the city from Nova Scotia.

The holiday lights were turned on Thursday, Dec. 1, during the annual Tree Lighting on Boston Common ceremony, which is hosted by Mayor Martin J. Walsh’s office.

Since then, lights around the park have sporadically gone dark. And Jamie McGrath, the contractor’s project manager, said the squirrels are to blame.

“It’s a pain,” he said. “It’s worse this year than last year. . . . They seem to be more and more aggressive.”

McGrath said the issue reached a fever pitch prior to the lighting ceremony. In the nine days leading up to the event, crews were constantly having to replace the lights in preparation of the celebration. He said the animals typically chew through the wire where it meets the sockets.

The company turned to using “Critter Ridder,” an organic product that drives the animals away, to deal with the problem.

McGrath said he hoped that, with the lights on all the time now, the squirrels “won’t be attacking it so much” because it can get expensive for the company to replace the decorations.

“It’s been less and less,” he said. “But they still go at it. . . . It’s still occurring.”

A squirrel on the Boston Common.David L. Ryan/Globe Staff/Globe Staff

Woods said reports about lights being out on some trees have been lodged by people passing through the park on late-night strolls.

“We are getting many calls of people noticing it,” he said.

When a report comes in, the city files a work order that the contractor is obligated to fulfill. One report filed on the city’s 311 app last Wednesday said the giant spruce tree was “missing half its lights.”

The city closed the case after YES took care of the issue. “Repaired wiring that squirrels chewed up, Christmas tree lights working again,” the city noted on the 311 site.

When asked why the squirrels keep going after the colorful lights, McGrath laughed and said: “I don’t know. You’re going to have to ask the squirrels.”