We all know we're supposed to show up to work on time, respect our managers, and meet deadlines as assigned. But here are a few things not to do if you want to succeed on the job.

1. Complain too much

It's one thing to occasionally express your displeasure with the way work situations are being handled, but if you get into a routine where you're griping to your coworkers on a consistent basis, you'd better change your ways.

First of all, nobody likes a complainer, but more so than that, the more you moan about the office, the greater your chances of saying something out loud that could get you into trouble. If you're having difficulty coping with your workload or dealing with a troublesome colleague, talk it out with your partner, buddy, or therapist and keep your cool while you're on the job.

2. Volunteer all the time

Going above and beyond the regular call of duty is a good way to get in your manager's good graces, and possibly even advance your career. But one thing you shouldn't do is be that person who's constantly volunteering to take on more work or pick up other people's slack. Not only will you risk having others take advantage, but you'll potentially spread yourself too thin, at which point your overall performance might suffer.

3. Dress inappropriately

Many offices these days are adopting a casual dress code, and while that might be good for your comfort and wallet, it also opens the door to poor decisions. No matter how laid-back your office environment might seem, don't make the mistake of wearing clothing that's too revealing, ripped, or just plain unlaundered.

Along these lines, avoid t-shirts with potentially offensive language or slogans. You have plenty of opportunity to express yourself outside the office, and while it's one thing to swap your dress slacks for jeans, it's another to sport an outfit that blatantly exposes your midriff.

4. Talk politics

Most office environments lend themselves to non-work-related conversations from time to time. But while it's OK to rehash your weekend plans or engage in some mild sports-related trash talk, bringing politics into the workplace is generally a bad idea (especially today). Not only are politics a personal matter, but discussions around them tend to get heated, and the last thing you want is to create an atmosphere of bad blood because you and a coworker don't see eye to eye.

5. Spread rumors

Nobody likes a gossip, but that's not the only reason to avoid spreading rumors or badmouthing your coworkers, even if justifiably. Under the wrong circumstances, you could end up with a serious HR violation on your hands. If you really need to get your gossip on or blow off steam, find a friend with an open ear and have those conversations outside the office.

6. Spend too much time on personal calls, social media, or anything else that isn't work-related

Even if you work in a busy, bustling office, there's a good chance someone is keeping track of your work habits. It might be your manager or a coworker with a chip on his shoulder, but that person is bound to notice if you're spending hours browsing on social media or chatting away on the phone.

Furthermore, you never know what data your company might be tracking, so if you're using its network or internet, be wary of patterns that could get you into trouble.

7. Come in contagious

Many companies don't distinguish between vacation and sick days, which means that if you're under the weather, you might be tempted to drag yourself into the office and reserve your time off for something fun. But while it's OK to come in with a moderate case of the sniffles, if you're running a fever, coughing up a lung, or experiencing any sort of serious digestive upheaval, you'll be doing your coworkers a favor by just staying home. If anything, explain to your boss that you're well enough to work but are carrying germs, and you might get permission to do your job from home that day.

8. Steal your coworkers' food

This one should really go without saying, but of all the workplace sins to commit, there's perhaps none more egregious than busting into the communal fridge when no one's looking and helping yourself to a meal that isn't yours. Desperate times might call for desperate measures, but if you're too swamped to grab a sandwich from the corner deli, beg a coworker to do it for you and keep your hands off other people's grub.

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Even if you're an otherwise star employee, these eight habits could get you in trouble at work. If you're serious about succeeding on the job, make sure to avoid these mistakes at all costs going forward.