We can all spot terrible employees: they under-perform, they don’t work well with teams, they struggle to meet expectations… but oddly enough, it isn’t the obviously terrible employees who cause the real problems.
Whether clearly incompetent or unbelievably lazy, they’re easy to spot. So although it’s never fun to fire people, at least you know there’s a problem–and you can quickly let such employees go and move on.
The real problems are caused by employees who appear to be doing an OK job but meanwhile act like what a friend once called an “insidious cancer,” slowly destroying other employees’ performance, attitude, and morale — and with it, your business.
Here are not so obvious signs an employee is poisoning your company.
Dispatches From The Front 