)rder CHIROPTERA 



65 



lies of bats are easily recognized by the mounds of guano and 

 ometimes by the presence of dark stains on the ceilings where 

 lusters of bats have been suspended. The known distribution, 

 n the United States, of five species of bats having a limited 

 ange in Illinois is shown in fig. 50. 



Economic Status. — Bats in Illinois are undoubtedly bene- 

 icial because they feed primarily on insects and aid in reducing 

 he numbers of some important pests. Colonies of bats in build- 



GRAY BAT 



SOUTHEASTERN 

 BAT 



SOUTHEASTERN 

 BIG- EARED BAT" 



Fig. 50. — Known distribution, in the United States, of bats with 

 L restricted range in Illinois. 



