262 



Descriptive Zoology. 



Rats and Mice. The rats and mice are of many kinds 

 and of vast numbers. Man has adopted some kinds of 

 animals, but these creatures may be said to have adopted 

 man. They are universal attendants on civilization and 

 are as cosmopolitan as man himself. The length of time 

 that they have been associated with man is hinted at 

 by the fact that the word for mouse, in essentially the 



FIG. 154. CHIPMUNK. 



From photograph from Recreation, by permission of G. O. Shields. 



same form, is found in many languages. Though they have 

 many enemies besides man, it seems impossible to exter- 

 minate them, for they are protected in many ways, espe- 

 cially by their nocturnal habits, and, as Coues says, by 

 their very insignificance. 



Beavers. The largest rodent found in the United 



