Wayne White of American Pest scouts the Washington Post newsroom for signs of mice. (Jahi Chikwendiu/The Washington Post)

Wayne White walked into an office building in downtown Washington, trying to think like a mouse.

His expert eye took in the things that make a rodent feel at home amid the cubicles: the half-finished salad on one desk, the communal box of cinnamon buns on another, the piles of paper, the utility conduits that are subway tunnels to the tiny. And in the surrounding ergonomic chairs, the biggest vermin enablers of all: Us.

Mice aren’t just eeking (sorry) out a living in Washington offices, they’re thriving. Along with roaches, rats and other creepy crawlies, they are as common in the fluorescent habitat as lawyers and lobbyists. The little opportunists share space with the big opportunists in congressional suites, intelligence bunkers and newsrooms (more on that later).

President Andrew Johnson was known to feed mice at his desk. Barbara Bush once swam with a rat she described as “enormous” in the White House pool. (She credited her springer spaniel Millie and the country’s commander-in-chief with drowning it.) Jimmy Carter grew furious when the General Services Administration and the Interior Department argued over which agency was responsible for the dead mouse he smelled in the walls of the Oval Office.

“I doubt there’s an office building in Washington that doesn’t have them,” said White, director of technical services for American Pest, which treats millions of square feet of office and commercial space around the region.

A partially eaten apple danish and sunflower seed shells are spotted near the loading dock of the building that houses The Washington Post. (Jahi Chikwendiu/The Washington Post)

What makes the office mouse different from his house and church cousins is the human ecosystem of the workplace. In the mixing bowl of an office, there are widely different views on food handling and cleanliness, and then a lot of finger pointing when the rodents come sniffing for crumbs. Further, staffers who are terrified of mice often clash with those who want to protect them.

“Mice in offices are a different situation,” White said. “Sometimes a person will say ‘I hope you’re not going to hurt them.’ And the person next to them will say, ‘I hope you’re going to nuke them!’ ”

White has known animal-loving office workers to spring the traps he has left behind, turning mouse bait into mouse hors d’oeuvres.

Those tensions may be particularly high in Washington, where eating-at-your-desk is a daily ritual for many, and animal welfare is a local industry.

Even at the Dupont Circle headquarters of People for the Ethical Treatment of Animals, there are mixed feelings about pest control.

“ ‘Pests,’ I don’t like that word,” said PETA founder Ingrid Newkirk.

When Newkirk found mice in her office a few years ago, her instinct was to applaud. But one of her animal-rights activists was so unnerved by the sight of a mouse dropping, she wanted to work from home. Newkirk — who considers mice “unobtrusive role models” — told the woman to “man up.”

“They are one 200th your size and they are harmless,” she said. “Live and let live, for God’s sake.”

Eventually, they released the mice outside and sealed all the cracks they could find. More recently, Newkirk used nail-polish remover to free a beetle she found stuck to a strip of tape on a FedEx package. Two people objected to bugs in the office kitchen.

“I told them ‘They only come out at night,’ ” she said. “ ‘If you’re nervous, send someone in to turn the light on for you.’ ”

Mice in the workplace

This is a non-scientific user poll. Results are not statistically valid and cannot be assumed to reflect the views of Washington Post users as a group or the general population.

When it comes to rats, however, White said office workers tend to be more unanimously anti-rodent. “Most people are willing to pull out all the stops with rats,” he said.

This being Washington, few office building managers or bureaucrats were willing to discuss their mouse sightings on or even off the record. Spokespeople for the National Security Administration, the Architect of the Capitol and National Geographic all declined to confirm reports of office vermin.

One example of a more robust reaction: Blood-curdling screams aren’t common in The Post’s newsroom (even during a political season like this one). But just such a shriek recently shook the cubicles of our brand-new downtown offices. “The first thing I thought was ‘active shooter,’ ” said one shocked reporter. But word quickly spread: Mouse.

Mouse sightings were common in The Post’s previous home, a decrepit 50-year-old building with many a cluttered desk and decades’ worth of sandwich scraps. Had the little guys followed the staff to the shiny new high-tech space a few blocks away?

Maybe, according to Jay Nixon, a former president of the National Pest Control Association, who counts the State Department among his one-time clients. (He was once sent overseas to deal with rodents in an embassy.) Mice have been known to stow away in packing crates or office furniture. But it’s just as likely that the animals came in during the renovation of the new offices, when there was lots of access to outdoors and lots of construction worker lunch scraps to be had.

“Office buildings are inhospitable places for mice, until you introduce food,” Nixon said. “But once you do, it becomes Shangri-La. [Offices] are warm, with lots of passages through the walls and ceilings, and they are empty at night.”

And in a snacking culture, the food always shows up. (White still has the half-eaten, foil-wrapped chocolate truffle he once found on the desk belonging to an office dweller he would only describe as “a former secretary of state who is now running for president.”)

Nixon has inspected hundreds of infested office buildings and always looks first for what he calls the “office 7-Eleven.” Someone always keeps cache of cookies and crackers, and not everyone keeps them properly sealed.

Nixon remembers a frustrating mouse problem at a local military facility. Technicians looked in vain for a source of food. Except for one secret place.

“There was a restricted area on the fourth floor,” Nixon said. “When they finally let us up there, we found it. Wrappers everywhere.”

At the office of an environmental group, it was easier to track down the source of a fruit-fly outbreak: A five-gallon bucket of food waste one staffer was keeping at his desk. “It took a supervisor to say, ‘No, you cannot compost at work.’ ”

White agreed to come evaluate The Post newsroom. (But not to treat it; the building owners have already dispatched a pest-control team, and no mice have been spotted lately.) Rooms filled with journalists are often rich habitats for rodents because piles of old papers and stacks of notebooks make good nesting material, not to mention their crumb-dribbling ways.

But he deemed the new office, which The Post occupied in December, remarkably clutter free and clean. (Give us time.)

Even the spaces under the office refrigerators and microwave were still pristine. White did find plenty of snacks, half-eaten lunches and a table full of candy for sale. But most of the treats were properly sealed, and the food scraps wouldn’t feed the mouse as long the trash was emptied each night.

“It would be unusual to have a significant infestation in an office like this,” he said. “Sometimes it’s hard to know if you’re seeing three mice, or seeing one mouse three times.”

For some employees, a single sighting is enough to trigger what psychology texts call “musophobia,” an extreme fear of mice. In an office, a person who keeps mice as pets may share a desk with someone who breaks into a sweat at the words “Stuart Little.”

“It is a very real phobia,” said Sally Greer, a clinical psychologist in Alexandria, Va. The fear usually stems from some kind of traumatic exposure early in childhood, maybe a movie, maybe being startled by a mouse in a hallway, maybe seeing a parent react to a rodent with terror. “Somehow you got the message, this object is to be feared.”

White quickly found a few of the defensive perimeters that some newsroom residents have thrown up since that musophobic scream was heard. An ultrasonic rodent repeller was plugged into one wall. Two people said they had taken to wearing boots and one said she spent much of the day holding her feet off the floor.

One staffer in the Metro section was packing her lunch trash into a zip-top bag. She had been surrounding her desk with cotton balls soaked in peppermint oil as a deterrent — per Google — but the cleaners swept them away every night. “Now I just spray the oil on the carpet.”

White nodded. “The best sign is that they clean that well here,” he said. Of the efficacy of peppermint oil, he would only say “There just isn’t any science behind it.”

To which a Washington mouse-o-phobe can only say: “Rats.”