210 ECONOMIC ZOOLOGY 



are the smallest of all mammals. They usually live on the ground or 

 in holes and [are easily mistaken for [mice. While their habits are 

 not very well known they are doubtless valuable insect destroyers. 



Moles are sometimes used as food, but their small size and com- 

 paratively small numbers makes them of no importance in this way. 



Hedgehogs are sometimes used as food. They may be covered with 

 a layer of clay, which peels off, when the animal is removed from the 

 fire, bringing the spines of the animal with it. The hedgehog is not 

 found in North America. 



Chipptera. Bats. The bats are at once recognized by their large 

 membranous wings, the digits of the fore-legs being enormously elon- 

 gated and connected by thin membranes of skin. Their power of flight 

 has caused them to be widely distributed, often in places inaccessible 

 to other mammals. There are more than 600 species of bats, 

 varying from a few inches in expanse of wings to 5 feet, in the " flying 



FIG. 134. Little brown bat, Myotis lucifugus (Vespertilio subulatus.) X%. 



foxes" of the Orient. They are usually nocturnal and spend the day 

 hanging head-down in some cave or other dark place. In certain lime- 

 stone caves they may be found hibernating in enormous numbers. 

 They fly through the intricate and totally dark passages of these caverns 

 with perfect ease and certainty, owing to the possession of a certain 

 marvelously acute tactile sense that warns them of their near approach 

 to solid bodies. 



A few large oriental and other tropical bats are fruit-eaters and 

 are quite destructive to figs and other tropical fruits, especially since 

 they often travel about in groups. 



Most bats, however, are insectivorous, and, being nocturnal in habits, 

 destroy many forms that would not ordinarily fall prey to birds. It is 



