EDIT: OK, on reflection I'm less confident in all this. Feel free to read my original comment below.

I have a theory that a high male-to-female ratio actually triggers creepy behavior in men. Why?

Creepy behavior has an evolutionary purpose, just like all human behavior. The optimal mating strategy changes depending on my tribe's gender ratio. As nasty as it sounds, from the perspective of my genes it may make sense to try to have sex by force, if it's not going to happen any other way.

I suspect evolution has programmed men to be more bitter, resentful, and belligerent if they seem to be in an area where there aren't many women. Hence you get sexual assault problems in the military, countries with surplus young males causing various forms of societal unrest, etc.

In other words, maybe it's not that individuals are creepy so much as men "naturally" act more rapey if there are only a few women around. Of course, we're all adults and we can supress unwanted internal drives, but it may also be a good idea to attack the root problem.

So in light of this, some possible solutions for male creepiness:
* When men feel desperate, they act creepy. That doesn't necessarily mean we should treat these men like bad people. Yes, these are antisocial behaviors. But they're a manifestation of internal suffering. So, try to feel compassion and respect for people that are suffering, in addition to letting them know that their behavior is antisocial.
* If you're a man and you notice yourself acting creepy, one idea is to try to get interested in something that's got a decent number of women involved with it. (Possible examples: acting, dancing, book clubs. Maybe other commenters have more ideas?) Hopefully, this will program your subconscious to believe you're no longer in a desperate situation. In the best case, maybe you'll find a girlfriend.