Morning Edition, October 11, 2006 · A UCLA study says women tend to put their best fashion foot forward when they are most fertile. In the study, a panel of men and women looked at photos of college students taken during their most and least fertile phases of the month. Researchers say the judges picked the photo in the fertile phase 60 percent of the time. Other animals release powerful scents, or change color, when they are ready to mate. Apparently, women just need to go shopping.