CURIOUS PECULIARITIES 161 



shelled insects. The fruit-bats, however, have molars of a 

 very different sort, with rather smooth crowns, for crushing 

 instead of cutting. The blood-sucking vampire bats of 

 South America have very large canine teeth with sharp, cut- 

 ting edges, and even the molar teeth are formed with scissor 

 edges, very much like the teeth of cats. 



The teeth and skulls of bats exhibit many interesting and 

 even extraordinary variations, but it is impossible to enumer- 

 ate them here. The species illustrated on page 172 is fairly 

 typical of the bats found in the United States. 



As previously remarked, very little is known regarding the 

 habits of bats, chiefly because their nocturnal habits make 

 it very difficult to find them, or to observe them. We know 

 that in winter some of our species live in caves, in a semi- 

 dormant condition. Dr. C. H. Eigenmann says, of the thou- 

 sands that inhabit Mammoth Cave, "they fly readily if dis- 

 turbed in summer, but in winter they hang apparently dead. 

 If disturbed, a few respiratory movements may be seen, and 

 they may utter a few squeaks, when they again remain ap- 

 parently lifeless. If knocked from the roof some of them 

 fall to the bottom of the cave and flap about, others fly away. 

 I have seen them leave a cave in midwinter, after being dis- 

 turbed, but fly no further than a hundred yards, then turn 

 and enter the cave again." 



In central Montana, where there are no trees, I once 

 found a large colony of bats inhabiting a cave that a sub- 

 terranean stream had washed under the prairie. In Arizona 

 there is a cave which is said to contain "a million" bats. 

 Once while hunting elephants in the Malay Peninsula, the 



