For you guys who believe that bugs don't consciously aim I offer this true story.
Once while riding a motorcycle I passed under a tree that had branches overhanging the road. Shortly afterwards I felt quite abit of pain from my posterior. The pain grew worse and in a near panic that almost resulted in a locked up front brake I pulled off the road and dropped my drawers and upon running my hands over my butt I knocked several large ants off. Unfortunately, not before they put enough welts on my behind to impress my father, if he had been around to see.
I had been riding for probably an hour when this happened so I doubt they'd been hiding in my 501s all that time and just then either got mad or hungry. They must have come from the overhanging branches I had passed under.
This happened at least 10 years ago and I still wonder how those bugs timed that jump. I have no doubts that they will evolve past us someday.