60 



ORDERS OF MAMMALS— BATS 



From the bats of the United States, there is 

 nothing to fear, for their claws and teeth are 

 pitifully weak. One cross old "bumble-bee," 

 angrily bumbling, is more dangerous to a peace- 

 ful community than all the bats of our country 

 taken together. In some portions of South 

 America, however, the vampire bats cause seri- 

 ous trouble. 



Keen-eyed boys and girls all over the world 

 should know that little is known concerning 



SKELETON OF PALE BAT. 

 Antrozous pallidus. 



the habits of bats, and much remains to be found 

 out. These creatures are therefore excellent 

 subjects for original investigation. 



The Order of Bats as a whole contains about 

 four hundred and fifty species, but it is safe to 

 say that three-fourths of them are known only 

 by their dry skins and skulls, and that their 

 habits are quite unknown. The questions are, — 

 why do bats live? Upon what do they feed? 

 Are they useful to man, or injurious? What 

 are their friends and their enemies? Do they 

 migrate, and at what times? Where do they 

 nest, or take shelter; and what are the facts 

 about their young? What parasites and dis- 

 eases have they? 



Although the bat is a true mammal, it is al- 

 most as wide a departure from the ordinary, 

 four-legged, land-going type as is a whale or 

 manatee. Its hand reveals an extreme degree 

 of what is called "specialization." For a mam- 

 mal, the arms are of great length. The bones of 

 the fingers are enormously extended, and con- 

 nected with hairless skin as flexible as india 

 rubber, to form a wing for flight. This wing 

 membrane is extended on up the arm to the 

 body and the legs, and is continued between 



the legs and tail, where it forms a supporting 

 parachute in flight. 



The thumb of a bat is very short and free; 

 and its nail is developed as a hooked claw, by the 

 aid of which the creature can comfortably climb 

 about or support itself. The favorite position 

 of a bat at rest is hanging by'its feet, head down- 

 ward. 



To be "as blind as a bat" is not to be blind 

 at all, but rather to possess powers of vision that 

 are uncommonly good in semi-darkness, or at 

 night, and fairly good even in the broad light 

 of day. When disturbed at midday, all the 

 bats I have ever seen alive (perhaps twenty 

 species in all) have flown away to places of se- 

 curity as briskly and successfully as so many 

 swallows. The eyes of all night-flying bats are 

 small, jet black, and look like tiny black beads, 

 but those of the day-fl} r ing fruit-bats are very 

 much larger in proportion. 



The teeth of bats of different species show 

 wide variation. In nearly all of the four hun- 

 dred and fifty species, the canine teeth are as 

 strongly developed as in the cat, and in some 

 bats their proportions are really formidable. 

 A careless examination of a bat's skull might 

 easily lead one to believe that it belonged to a 

 carnivorous animal. But the molar teeth will 

 always tell the true story. 



The insect-eating bats, which far outnumber 

 all others, have cheek-teeth which terminate in 

 sharp points, and are specially designed for cut- 

 ting to pieces the hard parts of hard-shelled in- 

 sects. 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, cutting 

 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 in- 

 teresting and even extraordinary variations, 

 but it is impossible to enumerate them here. 

 The accompanying figures show the characters 

 of two species 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. Br. C. H. Eigenmann 



