Oddly enough, it isn't the truly terrible employees who cause the real problems.

Some people obviously deserve to be fired: Whether clearly incompetent or unbelievably lazy, they're easy to spot. So although it is definitely painful, you can quickly let them go and move on.

The real problem is the employee who appears to be doing a satisfactory job but meanwhile acts as what a friend called an "insidious cancer" and slowly destroys other people's performance, attitude, and morale--and with it, your business.

Here are eight qualities of employees you absolutely must address--or, worst case, cause you to let that employee go:

1. They say, "That's not my job."

The smaller the company, the more important it is that employees can think on their feet, adapt quickly to shifting priorities, and do whatever it takes, regardless of role or position, to get things done. Even if that means a manager has to help load a truck or a machinist needs to clean up a solvent spill; or the accounting staff needs to hit the shop floor to help complete a rush order; or a CEO needs to man a customer service line during a product crisis. You get the idea.

Any task an employee is asked to do--as long as it isn't unethical, immoral, or illegal, and as long as it's a task "below" his or her current position--is a task an employee should be willing to do. (Great employees notice problems and jump in without being asked.) Saying, "It's not my job," says, "I care only about me." That attitude quickly destroys performance, because it turns a cohesive team into a dysfunctional group of individuals.

2. They think they've paid their dues.

You did great things last year, last month, or even yesterday. We're appreciative. We're grateful. Unfortunately, today is a new day. Dues aren't paid. Dues get paid. The only real measure of any employee's value is the tangible contribution he or she makes--daily.

Saying, "I've paid my dues" is like saying, "I no longer need to work hard." And suddenly, before you know it, other employees start to feel they've earned the right to coast, too.

3. They think experience is a tangible commodity.

Experience is definitely important, but experience that doesn't translate into better skills, better performance, and greater achievement is worthless. Experience that just "is" is a waste. (Example: a colleague once said to us younger supervisors, "My role is to be a resource." Great, but then he sat in his office all day waiting for us to come by so he could cast his pearls of wisdom. Of course, none of us did--we were all busy thinking, I respect your experience, but I wish your role was to do your job.)

How many years you've put in pales in comparison with how many things you've done.

Saying, "I have more experience" is like saying, "I don't need to justify my decisions or actions." Experience (or position) should never win an argument. Wisdom, logic, and judgment should win--in whomever those qualities may be found.

4. They lead the meeting after the meeting.

You have a meeting. Issues are raised. Concerns are shared. Decisions are made. All in attendance fully support those decisions. Things are going to happen. Then someone holds the "meeting after the meeting." Now he or she talks about issues he or she didn't share earlier with the group. Now he or she disagrees with the decisions made.

And these people even say to their teams, "Look, I think this is a terrible idea, but we've been told to do it...so let's at least give it a shot." And now, what was going to happen never will. Waiting until after a meeting to say, "I'm not going to support that" is like saying, "I'll agree to anything, but that doesn't mean I'll actually do it. I'll even work against it."

Those people need to work somewhere else.

5. They revel in gossip.

Before a meeting, we were talking about supervisors in another department when our new boss looked up and said, "Stop. From now on we will never say anything bad about anyone unless they are actually in the room. Period."

Until then, I never thought of gossip as a part of a company's culture--gossip just was. We all did it. And it sucked--especially because being the focus of gossip sucked. (And in time I realized people who gossip suck, too.)

If an employee has talked to more than one person about something Martha is doing, wouldn't everyone be better off if he stepped up and actually talked to Martha about it? And if it's "not his place" to talk to Martha, it's definitely not his place to talk about Martha.

Saying, "Did you hear what he did?" is like saying, "I have nothing better to do than talk about other people." Not only do employees who create a culture of gossip waste time better spent on productive conversations, but they cause other people to respect their co-workers a little less--and anything that diminishes the dignity or respect of any employee should never be tolerated.

6. They use peer pressure to hold others back.

The new woman works hard. She works long. She's hitting targets and exceeding expectations. She rocks. And she eventually hears, from a more "experienced" employee, "You're working too hard, and you're making the rest of us look bad."

Where comparisons are concerned, a great employee doesn't compare herself with others--she compares herself to herself. She wants to "win" that comparison by improving and doing better today than she did yesterday.

Poor employees don't want to do more; they want others to do less. They don't want to "win." They just want others to make sure they don't lose.

Saying, "You're working too hard" is like saying, "No one should work hard, because I don't want to work hard." And pretty soon very few people do--and the ones who keep trying get shunned for a quality you need every employee to possess.

7. They rush to grab the glory...

OK, maybe he did do nearly all the work. Maybe he did overcome almost every obstacle. Maybe, without him, that high-performance team would have been anything but.

But probably not. Nothing important is ever accomplished alone...even if some people love to act like it.

A good employee and good team player shares the glory. He credits others. He praises. He appreciates. He lets others shine. That's especially true for an employee in a leadership position--he celebrates the accomplishments of others secure in the knowledge that their success reflects well on him, too.

Saying, "I did all the work" or, "It was all my idea" is like saying, "The world revolves around me...and I need everyone to know it." And even if other people don't adopt the same philosophy, they resent having to fight for recognition that is rightfully theirs.

8. .... And they rush to throw others under the bus.

A vendor complains. A customer feels shortchanged. A co-worker gets mad. No matter what has happened, it's someone else's fault.

Sometimes, whatever the issue and regardless of who is actually at fault, some people step in and take the hit. They willingly accept the criticism or abuse, because they know they can handle it (and they know that maybe the person actually at fault cannot).

Few acts are more selfless than taking the undeserved hit. And few acts better cement a relationship. Few acts are more selfish than saying, "It wasn't me..." especially when, at least in part, it was.

Saying, "You'll have to talk to Martha" is like saying, "We're not all in this together." At the best companies, everyone is in it together.

Anyone who isn't needs to go.