x-rated moth whoopie

As winter approaches, I spent several hours yesterday weeding the back garden and trying to make ready the earth for the first freeze. The entire time I was engaged in this task, these two moths were bouncing and flopping all over the yard making, what I can only assume, was moth whoopie.
















It was quite an amazing thing to witness at all but what really struck me was that these two moths could even find each other in the first place. Its not as if I see huge gray and orange moths everyday, in fact I've only seen one, one other time and it was on a different continent. I wonder if they have a pre-arranged meeting place etched on their little moth psyches that gets passed down, generation after generation...