Skeletons: Skeleton imagery pervades this holiday. In pre-Columbian times, the Day of the Dead was celebrated in August. It now takes place on Nov. 1 and Nov. 2, coinciding with the Catholic holidays of All Saints' Day and All Souls' Day. Karen Castillo Farfán/NPR hide caption

itoggle caption Karen Castillo Farfán/NPR

Vampire bats are common in Central and South America, where they feed on livestock and sometimes people. Michael & Patricia Fogden/Corbis hide caption

itoggle caption Michael & Patricia Fogden/Corbis