http://www.npr.org/templates/story/story.php?storyId=123330735

Every year, an enormous migration takes place in Western Europe.
Millions of moths fly for days, riding wind currents southward in the fall and
north in the spring.

Scientists thought these insects were simply blown to their destinations, but
now they've discovered something remarkable: The moths actually select the
fastest wind currents, and even change course to shorten their trip.

Thanks to Brad Gryder