I (a hetero male) have been sexually harassed by a woman in the workplace. What you call "normally vaguely annoying behaviors" I called "being stared at like I was a piece of meat."
Im pretty sure its horrible (not kidding). Im also pretty sure it doesnt qualify your entire workplace as "rampant misandry" and im not 100% convinced (but i may be wrong if you actually tried to solve the problem in other ways) it requires the intervention of HR.