There is a large Tupperware on Pat Myshrall's desk by the Hubbard-side window of H-L Library, full of doggie treats that have an unrivaled crunch and smack of steak tartar. Professor Paul Franco's black lab, Reggie, bounds up to Pat's window every morning for his snack, as do Mr. Jones, Bean, Sam and Charlie, the other Bowdoin dogs who know her like true Pavlovian disciples, conditioned by her legendary doggie treats and her crooning affection.

But until recently, someone else had been getting into Pat's Tupperware. And he's not a dog. Nor has he ever been invited. And before he was caught in Librarian Sherrie Bergman's Havahart Live Animal Trap last Saturday, the squirrel—dubbed Mr. Knightley by the library staff—had stolen candy from the library after breaking and entering countless times.

The library staff relishes sharing their Mr. Knightley anecdotes, and when I came in to visit, their stories about the squirrel came down like acorns on a windy fall day.

"I was sitting right there at my desk by the window, and all of a sudden I felt a swishing on my face. I thought it was my hair," said Barbara Harvey, circulation and government documents assistant. "Then I felt a paw on my cheek. Mr. Knightley was sitting on my shoulder."

Donna Van Dyck, the ordering assistant in technical (tech) services, saw Mr. Knightley scrupulously putting the netting protecting a Quad-side window into his mouth one bite at a time, and then sneaking away with his trophy to a tree. Someone else chimed in that he has also been spotted dragging large items like peanut butter jars across the Quad. Digital Technology Integration Librarian Mike McDermott even saw him "casing the joint," citing Mr. Knightley's subtle inspection of the various windows of the library, undoubtedly searching out an entryway for a future break-in.

It was Mr. Knightley's frequent visits to the library that earned him his nickname.

"He was such a pet, you had to name it," said Pat. "We named him after—oh dear, Barbara, what was it?" Pat has a low and soothing voice, and she looks like everyone's favorite nanny. "You know dear, I just can't remember. From Jane Austen. 'Persuasion,' was that where Mr. Knightley came from?" She thought for a moment.

"It was 'Emma!'" said Barbara Harvey from the circulation desk, suddenly remembering that the squirrel was named after Emma's judicious and honorable suitor.

"You know, there's a three-year rule with pets," said Pat slowly. "When they've been around for that long, you get to name them."

Lucy Smith, receiving coordinator in tech services, believes there is more than one Sciurus carolinensis in the library. She wrote a "tactical report" on Mr. Knightley's first foray into H-L in May, when he bounded through a two-inch open window, flinging himself from cubicle to cubicle like a trapeze artist on the run.

"It's obvious that there is a squirrel terrorist cell in the immediate environs of H-L," she wrote an email to the library staff on May 25. "It will wreak havoc on staff morale to remain constantly alert to screams and other startling behavior resultant from surprise squirrel attacks. We urgently request that Headquarters' top brass investigate remediation measures."

Other members of the library staff treated Mr. Knightley's raids with similar gravity.

"Homeland Security has branded today a RED ALERT day for potential squirrel attack," Sherrie informed the staff in an email response on the same day. Phyllis McQuaide, former supervisor at the circulation desk, assigned students to squirrel lookout posts, H-L employee Greg Stowe suggested starting "serious negotiations," while Dan Cunningham in tech services went as far as to recommend mandatory musket training for the library staff.

Guy Saldanha, InterLibrary Loan supervisor, explained the legal procedures underway against Mr. Knightley after he'd been trapped in a Havahart last weekend.

"We were afraid he would not receive a fair trial," said Guy. "So he was brought to South Harpswell pending arraignment." Guy added that Mr. Knightley's assaults appeared suspiciously well-planned.

"He was very familiar with the layout of the library," he said. "I don't want to say it was an inside job, but we're not ruling out purposeful negligence on the part of the staff."

Sherrie blamed the recent squirrel intrusions on the architecture of H-L. There are no steps leading up to the entrance, she said, and the windows are low to the ground and have no screens.

"The library is squirrel-compliant," she said.

After the flurry of squirrel stories, everyone went back to their desks to work. Sherrie walked by Pat's desk on her way back to her office. "Oh, Sherrie, I forgot to tell you," said Pat. "There's a mouse in admissions."

-Sam Frizell