Over the span of my career, I’ve worked in just about every kind of environment you can imagine. But from the small startup that used moving boxes for tables to a giant global institution with hundreds of thousands of employees, there’s one thing they all had in common: the nosy colleague.

So, it’s probably a safe bet you’ll run into this challenging species in your career, too—if you haven’t already. Fortunately, most of the time, a nosy colleague isn’t anything more than an annoyance. But every once in a while, you’ll come across an overly curious co-worker who crosses a line. And, if you don't handle the situation carefully, it could cause issues for your career.

Here are three classic nosy colleagues, plus how to deal if you’re ever confronted with one.

1. The Talker-Turned-Taker

Most of the time, Chatty Cathys are pretty harmless and a normal part of your office culture. From chatting by the water cooler about your weekend plans to pondering what your co-workers are cooking up for the next big team meeting, friendly conversation is a great way to get to know your colleagues on a more personal level and share a bit about yourself, too.

But occasionally, there's someone who uses that break room chatter to his or her own advantage. Here’s one example from early on in my career: When I was new in the office and trying to get to know everyone, one woman really seemed to be going out of her way to give me the “real story” on how the place worked, including the latest in office politics and gossip. Along the way, she asked me to fill her in on my own projects, and I didn’t see the harm in confiding in her.

Until, that is, several months later. I’d started a major project and was set to present my findings to my boss, when I learned that she’d taken it upon herself to “help” me with my presentation. She volunteered to check in with my boss to help make sure I was on the right track (which I had OK’d)—but instead, she had swooped in and taken all the credit for my hard work.

How to Deal

Let’s face it: Information is power, and power-hungry chatty colleagues will use whatever information you share to get an edge. So, when a curious colleague has burned you—whether it’s stealing your ideas or revealing your secret crush on Bob in accounting to the entire third floor—you can block that power play by keeping your conversations to quick, friendly chats.

After this experience, I made it a point to keep my office conversations to a minimum with this woman. I also always had an alibi just in case I was ever cornered: I carried around a notebook or had an “important email” to get out in mind so that I could politely excuse myself from the conversation when necessary.

2. The Lingerer-Turned-Lurker

In my last job, I would be completely engrossed in a spreadsheet—or worse, writing an email—and I’d notice the office know-it-all slowly walking by my desk.

At first, I didn’t think anything of it (other than, Seriously, doesn't this guy have work to do?). But one day, while writing a particularly sensitive email to a client, I was overwhelmed with this creepy feeling someone was watching me. I turned around, and my colleague stood right behind me, reading my email as I wrote it! Worse, he actually began to make suggestions about what I should say.

Unfortunately, this wasn’t an isolated incident: I’ve had a lurker at every office I’ve worked at. And while no, you shouldn’t have anything that you wouldn’t want your boss to read on your screen, anyone who invades your privacy (and offers unwelcome advice) is incredibly frustrating.

How to Deal

If someone is going out his way to put his nose in your business, call the snooping out. After that incident, I made a point to stop what I was doing every time this guy came by to turn around, face him, and politely ask how I could help him. A few times, when I caught him reading over my shoulder, I jokingly told him that if that email was meant for him to read, I promised to send him a copy. And it did the trick: After a few confrontations like that, his lurking subsided.

3. The Fan-Turned-Follower

Having co-workers who appreciate your work is pretty awesome. While it’s great to be appreciated by your boss, having the respect of your peers is a huge win—which makes this type of nosy colleague especially hard to spot.

Early on in my career, I’d made some suggestions to my team’s procedures that ended up being widely adopted throughout the company. One of my colleagues, who was a few years younger, was particularly impressed, and asked me to share all my “secrets” with her so she could step up her game as well. At first, I was flattered—who wouldn’t be?

But, before long, that flattery bordered on stalking. She began shadowing me on every project possible and even tried to mimic my writing style. While most of the time imitation is a sincere form of flattery, in a competitive work environment where everyone is trying to set themselves apart from the pack, having a carbon copy of yourself isn’t exactly ideal.

How to Deal

Have an office stalker? Turn the tables on her. In my case, instead of giving my colleague the opportunity to follow in my footsteps, I asked her if I could follow in hers. I spent less time detailing my methods and more asking her how she’d approach an issue. When she asked me how I was handling a sensitive situation with a client, I’d reply by telling her I was stuck. Then, I'd ask her advice on crafting an email or how to prepare for a difficult phone conversation.

And you know what? It’s a good thing I did. She turned out to be pretty fantastic at the job, and we eventually learned to collaborate productively and developed our own unique working styles as a result.

While curiosity may spell doom for the cat, it doesn’t have to do the same for your career. Keep your wits about you, and use these tips to maintain a healthy level of respect between you and your nosy colleagues.

Photo of people working courtesy of Shutterstock.