Situation: Walking down a steep hill behind a group of three girls.
One of the girls was constantly sneaking peeks in my direction (I was above the group).
A man running up the hill, training. As he passed the three he shot them a very obvious side-glance.
No overt response from the group, however they did become more animated ("vivacious" is a better word). You know how it is: when a group of women become the center of attention and they're enjoying it, they become more lively and louder (thus seeking more attention).
It's interesting, seeing things from a meta-perspective. At any rate, despite being interested in me that girl didn't approach. Fairly typical female behavior.
I prefer it when she approaches me. In my experience it's always the best.