It's Bat Week and the U.S. Department of the Interior has some interesting bat facts for you. Did you know that the largest bats have a wingspan of 6 feet? Or that they help spread seeds for nuts, figs and cacao -- the main ingredient in chocolate. So no bats, no chocolate. In 2006, a tiny bat from Siberia set the world record for longevity at 41 years. And I bet you didn't know that bats have belly buttons.