Western civilization has generally regarded bats with superstition, fear, and uncertainty. Too often, popular misconceptions have labeled them as "dirty," "disease carriers," or "blood suckers," an unenviable reputation to be sure. Only in China, expressed in art and handicrafts, has the bat achieved respectability as a symbol of happiness and good luck. This document attempts to dispel the fears and answer some of the questions most often asked of the National Museum of Natural History by presenting some general facts about the biology and natural history of these shy, nocturnal creatures. What are they? Bats are mammals belonging to the order Chiroptera, a name of Greek origin meaning "hand-wing," which accurately describes the animal's most unusual anatomical feature. The order is divided into two suborders, the Megachiroptera, consisting of a single family, the flying foxes and their Old World fruit and flower eating relatives, and the Microchiroptera, composed of the rest of the bat families, some 17 in all. These families are further classified into about 180 genera and over 900 species; only rodents have a greater number of species. Even though the names imply otherwise, not all Megabats are larger than Microbats. Although it is true that certain species of flying foxes have wingspans of up to 5 feet, one member of the Megachiroptera, the flower-feeding Macroglosus, has a wingspan of only 10 inches. However, some of the Microchiroptera are very tiny; the smallest is probably the Philippine bamboo bat, Tylonycteris pachypus, its forearm measuring only 22mm. and weighing only 0.05 ounce. The largest Microbat is the tropical American false vampire, Vampyrum spectrum, with a wingspan of up to 40 inches.