YMMV, but during my time studying the course coordinators of the first year CS courses had to put out a notice to the male students that the female students (greatly outnumbered) were there to learn and didn't want to be hit on during labs and tutorials. They did that because it had become a problem, especially as these courses consisted of a lot of students who perhaps didn't have much experience interacting graciously (or at all) with the opposite gender.