54 



AN ECONOMIC STUDY OF FIELD MICE. 



REPRESSION OE EIELD MICE— ACTIVE MEASURES. 



We pass now to a consideration of such means for the repression 

 of voles as are under the immediate control of the farmer. These 

 consist of trapping and other mechanical methods of destruction and 

 the use of poisons, fumes, and micro-organisms. 



TRAPPING. 



Trapping is a simple way to destroy field mice, but it is seldom 

 resorted to because few people have patience to follow it up per- 



Fig. 2. — Field mouse caught in baited guillotine trap. 



sistently and to look after the necessary large number of traps. 

 When field mice are abundant it is essential to use many traps and to 

 continue trapping for several weeks. Equipped with a hundred or 



Fig. 3. 



-Field mouse caught in unbaited guillotine trap. 



more effective traps, a good trapper should be able to make decided 

 inroads upon the numbers of the pests, if not to practically extermi- 

 nate them over a limited area. 



