Bungi Bill put it well.
The last time I saw them on my street there were two teenaged girls in dowdy long skirts being followed by an older man (that was creepy, really). I was in the kitchen and heard a barely audible tap on the front door, but by the time I'd gotten there the girls were far down the street I don't remember what they left in the door, but I do remember my impression that they certainly did not want to actually engage anyone at the door as they barely made any noise.
I was like that for quite a time at before I faded. Really did not want to talk to anyone as I thought what we had to say was embarrassing.