And the worst coworker behavior could happen a lot, given that over two-thirds of Minnesota's population is currently employed. What Is the Most Annoying Coworker Behavior in Minnesota? Zippia says the number-one most annoying coworker behavior in the U.S. is coworkers who are too loud, followed by coworkers who are lazy and those who love to spread office gossip. The Most Annoying Coworker Habits in AmericaThis annoying coworker behavior sometimes gets so bad that it's caused nearly two-thirds of us (about 57%) to consider leaving our jobs! While most of us have had to put up with some annoying coworker behavior from time to time, THESE people probably haven't.