The longer you're working with the same people and as you get to know your co-workers, certain traits will surely rear their irritating-to-no-end heads. Little habits that have nothing to do with work performance can really get under your skin — and even keep you from fully focusing on your own work. We manage to deal with them because unfortunately, we have to earn our paychecks and they're technically not doing anything wrong. And unless there's some kind of real sanitary issue that can be brought to the attention of human resources, your co-workers annoying habits are there to stay. What gets under your skin the most?