ANSWER: Gravity. The birds fly high with a heavy victim and drop it onto a splattering boulder. Many species of birds use this foraging trick on hard-shelled prey or nuts, reports "Behavioral Ecology" journal, dropping repeatedly, flying higher for harder food or if the ground below is softer. Crows are famous for doing this with nuts, knowing enough to fly lower and lower after multiple drops as the shell grows presumably weaker.

Herring gulls will often drop clams onto parking lots along the seashore, so many in one case as to imperil the people and cars below, says Tom Erdman, curator of the Richter Museum in Wisconsin. "The remedy? Gull silhouettes painted on the pavement, making the airborne droppers think competing birds were already waiting below to cop the food."

ANSWER: No wait at all. As recently as 1920 men and women in the U.S. enjoyed virtually equal life expectancy at birth--around 55 years.