Your co-workers are judging you. Beneath a veneer of professional collegiality, they're taking note of the mess on your desk, how loudly you chew, even your word choices.
Obviously, serious misconduct such as discrimination and harassment can lead to a job loss. But small irritants can hurt productivity and build walls between co-workers.
"Those little annoyances, like having a really sloppy work area or being a disgusting desk eater, can loom large," says Charles Purdy, senior editor at jobs site Monster.com.
To avoid negative judgments from your co-workers, experts advise avoiding the following behaviors.
1. Sucking up to the boss
The boss's pet who ingratiates himself at the expense of his co-workers incites negative judgments, says Meredith Haberfeld, a New York-based executive and career coach.
For example, Ms. Haberfeld consulted for a human-resources company where a junior employee pointed out his co-workers' mistakes after errors had been made.
"He created ill will with his colleagues because he didn't ever go to them to provide any insights while he saw the ship sinking," Ms. Haberfeld says. "Nobody wanted to work with him."
Trying to take work from your colleagues, or take too much credit, are also bad moves.
"These people are seen as overly self-interested and therefore untrustworthy and difficult to work with," Ms. Haberfeld says. "At a certain point, to go further in your career you need to not just be liked by your boss, you need support from your peers and people more junior."
The occasional bit of gossip can relieve stress. Too much can make you look bad.
"Sometimes it's fun to talk about the boss, but the person who is always complaining is widely disliked as well," Mr. Purdy says. "Toxic negativity makes people feel like you are not a good co-worker. People associate negativity with you."
According to a 2011 Monster.com survey, respondents reported that among their co-workers' impolite behaviors, gossiping "ticked them off," along with texting during meetings, being too loud and leaving a mess.
Employees also are judged when they interrupt colleagues, or ignore or discount others' ideas, says Peter Post, author and GREat-grandson of etiquette expert Emily Post.
"Those are the kinds of things that people remember for a long time. You are really attacking the person and belittling them," Mr. Post says. "They see you as a bully, and don't want to interact with you."
Complaining about "inappropriate" behavior that is, at worst, slightly off is also a problem. "It feels really condescending," says Art Papas, founder of TheFit.com, a website where workers complete anonymous surveys about companies' cultures. "Just because you're offended that doesn't mean you have to broadcast it."
Messiness, particularly in communal areas and shared workspaces, can breed negative judgments.
"Food that's left to become some sort of other thing in the refrigerator is really frustrating," says Mr. Post.
According to a recent survey from staffing and consulting firm Adecco, a majority of respondents said people are most productive when their workspace is clean, though some view messiness as a sign of being busy, and others see it as an indication of laziness.
4. Poor cubicle etiquette
In offices with few doors and lots of cubicles, etiquette with regard to odors and noise is important.
Microwaving last night's fish dinner for lunch in your cubicle today is a no-no. And your co-workers can sense if you didn't clean up after bicycling to the office.
But a loud talker may be the top offender. "If you need to concentrate and somebody is yapping, it can affect your work," says Margaret Fiester, operations manager for the human-resources knowledge center at the Society for Human Resource Management.
5. Not fitting in
It's important to fit into an office culture. That can include how you dress, and what you say.
"I was in a meeting the other day and somebody dropped the S-bomb. The third time they did it, it became unprofessional," Mr. Papas says.
There's also a code of conduct for email. "Maybe someone is overly brusque, or is always putting urgent or cc'ing everything," Mr. Purdy says. "Bcc is almost always a dangerous idea.
"Transparency is important—it prevents you from seeming sneaky. If you are bcc'ing someone to get someone else in trouble, you are being the office jerk."