This is the fourth in the “Limited Networker Field Guide” series.
Name: The Introverted Company Clumper
Environment: In large groups of similarly plumaged individuals
Behavior: When you attend a sit-down networking event, such as a lunch or a breakfast, you may sit down at an almost-full table only to discover that every single person there is from the same office.  You have just wandered into a flock of Introverted Company Clumpers. These strange birds attend networking events (usually at the behest of their supervisor) and then spend the entire time “networking” with their own co-workers.
Broken Rules of Good Networking: Your company is the wrong company. (Thank you, Scott Ginsberg) By sitting with the people from the office, the Clumper is not only denying himself the benefits of a good networking experience, but also denying the other participants who might want to meet him and start a new beneficial relationship.  Their worst offense, though, is to the poor person who happens to sit with them.  At best, they will lose the variety of potential networking contacts that should be available to them at one of these events.  At worst, they will be lefty wholly out of the conversation as Clumpers often spend their time speaking only with each other.
Counter-Measures:  In order to spare yourself from these uncomfortable situations, you may want to do a casual sweep of the table before sitting down.  Clumpers will often wear the same type of name badge, often with the company logo on it.  Another option that I use is to make sure that I reach my networking goal before I sit down.  That way any new people I meet are a bonus and not too much is lost in getting trapped with a bunch of Clumpers.
How We Can Help:  Of course, you should always be willing to engage those around you in conversation.  Just because they are all from the same office doesn’t mean that they all have the same interests, goals, etc. Use the INFER process to find out more about the person not the job.
If you are an event organizer, you can use several mechanisms to break up the Clumpers.  Use assigned seating if possible.  You can also use randomized seating.  At an event I attended not long ago we were each handed a playing card on entry and were told to sit at one of tables which corresponded to the suit on our playing card.