Walkin' Along, Readin' a Book

So, in all of my travels back and forth between house and elementary school (reading a book as I walk the couple of miles), I have re-wondered at a certain phenomenon.

Why is it that men who look like they're Mexican or at least from south of the United States think it's okay or funny to yell at me as they drive by in groups? I don't think it's very funny, especially when I jump because I was enthralled with my latest book. In fact, it calls to mind a scene in Little Women where Laurie's tutor closes the window and says, "We do not yell at women as if they were cattle," or something to that effect, before apologizing to the March girls.