An evolutionary trick

IN THE HEART of insect bite season, here's a reason to envy the crested auklet: The birds create their own bug repellent. Researchers from the University of Alaska-Fairbanks discovered that when the seabirds nuzzle potential mates, they are not merely courting; they are also transferring a citrus-scented secretion that includes chemicals called aldehydes, which repel ticks and other insects. To read more about Pacific seabirds, see this issue's feature "Seabird Signals."