4 



farmers' bulletin 932. 



Probabh^ no term api)lied to aiiiirials has been so generally mis- 

 used as the word " vermin." Originall^y restricted to small creepmg 

 animals, wormlike in their movements, and especially to insects, the 

 term has been broadened by P^nglish gamekeepers to include all 

 enemies of ground game. Usage now sometimes applies the term to 

 all animals that are supposed to be either harmful or useless. 

 Writers on game protection are often vehement in their condemna- 

 tion of " vermin,'' forgetting that what may be so considered by one 

 person may from the standpoint of another be highly useful. The 

 interests of the sportsman or gamekeeper often run counter to those 

 of his farmer neighbor, and they frequently clash on such matters 

 as rabbit protection an^ the enforcement of trespass laW'S. A better 

 understanding of the habits of birds and mammals, especially of their 

 food and the interrelation of species that prey and are preyed upon, 

 will greatly restrict the number of animals that may properly be 

 called " vermin." Under natural conditions f ew^ can rightly be so 

 designated: but man has interfered with nature until he has dis- 

 turbed its balance. He has introduced artifioial conditions and so 

 changed the environments of animals that some have prospered while 

 others have been driven out. The species that have been most favored 

 by man's activities are, unfortunately, those that have been most 

 harmful to his interests. As a result he must now make warfare 

 upon foes that were once inoffensive. 



HARMFUL NATIVE RODENTS. 



Only four of the many forms of wild rodents found within the 

 United States have been introduced ; the others are indigenous to the 

 countr}^ Among harmful native rodents are included the short- 

 tailed field mice, white-footed mice, cotton rats, kangaroo rats, pocket 

 gophers, ground squirrels, prairie-dogs, woodchucks, and rabbits. 

 A. few^ others occasionally do slight damage to crops or other prop- 

 erty. 



SHORT-TAILED FIELD MICE. 



Several groups, or genera, of short- tailed field mice occur in. the 

 United States and Canada, but only two of them have, by reason of 

 their abundance in cultivated regions, become serious pests. These 

 are commonly known as meadow mice ^ and pine mice ^ (fig. 1). 



Meadow mice are widely distributed, inhabiting most parts of the 

 Northern Hemisphere. In the United States w^e have many species, 

 but, fortunately, have thus far had no widespread plagues of the 

 animals like those that have occurred abroad. How^ever, there have 

 been manv local outbreaks, notably that of 1907~8 in the Humboldt 

 Valley, Nevada, where much of the alfalfa crop was utterly ruined. 

 Fortunately, few^ of our species come in contact with farm operations, 



1 Genus Microtus. 



2 Genus Pityj^nys. 



