620 TEXTBOOK OF ZOOLOGY 



tending into the South and Southwest, are the common forms. Be- 

 cause of their small size and retiring habits, these animals are seldom 

 observed. 



Order Chiroptera. — Bats are the mammals which have developed 

 the power of flight and are not always distinguished from birds by 

 the layman. The forearm and fingers are extended, and the skin 

 stretches between them as well as to the hind limbs. Most of them 

 are small and nocturnal. They usually have the toes of the hind 

 feet developed for grasping and are able to hang by them, head 

 downward, when at rest. The brown bat, Eptesicus fuscus, is the 

 most common form in the United States. The Mexican free-tailed 



Fig. 332. — Little brown bat, Myotis lucifugus, in resting position. (From Metcalf, 

 Textbook of Economic Zoology, published by Lea & Febiger.) 



bat, Tadarida mexicana, extends as far north as central Texas. Carls- 

 bad Caverns near the eastern boundary of New Mexico is famous for 

 its evening bat flight. The bats come out like a cloud of smoke, make 

 a definite flight of about sixty miles along two streams and back to 

 the caverns before daybreak. Here they remain until the next evening. 



Because of their ability to fly the bats are widely distributed 

 mammals, being found on all of the continents and even on isolated 

 islands. In the East Indies, Australia, Africa, and Asia, there are 

 several different fruit-eating bats. In tropical America there are true 

 and false vampire bats. The true vampires live on the blood of 

 horses, sheep, cattle, and occasionally sleeping human beings. Their 



