The Congress Avenue bridge in the city of Austin, Texas, is home to 1.5 million Mexican freetail bats for a period of six months in the summer, after the bats (62) from their home in Mexico. A quarter of all mammal species worldwide are bats, and there are 951 species of this strange mammal. The (63) they bring to the world of nature are that they are the important natural (64) of night-flying insects, for example, agricultural pests like the corn ear-worm moth; some bats also eat fish, fruit, frogs and birds. (65) bats are also important elements in rain forest ecosystems (66) they pollinate flowers and (67) seeds for countless trees and shrubs. Bats include the world’s smallest mammal, the bumblebee bat of Thailand, which weighs only a few grams, (68) the giant flying foxes that live in Indonesia have wingspans of just under two meters. It is well-known that bats use high-pitched sound which they (69) objects and off prey to establish their (70) . This form of radar is very (71) . In fact fishing bats have (72) echo location, so they can (73) tiny fish protruding only millimeters above a pond’s surface. African heart-nosed bats are said to (74) the sounds that beetles make when they are close to them. Bats are also (75) . One North American bat is (76) to the stings of scorpions and centipedes (77) which it feeds, while red bats that live in tree foliage throughout most of North America can (78) body temperatures down to freezing during winter hibernation. Bats can fly at between 20 and 50 kilometers an hour. Mexican free-tailed bats are (79) at using tail-winds to carry them over long distances at high speeds and they sometimes fly up to three kilometers high to feed. Bats are also social mammals, (80) the Mexican freetail bat colonies of Texas demonstrate. Mother Mexican freetail bats find and nurse their own young, (81) in the huge colonies where many millions of babies cluster at up to more than 5,000 per square meter.