THE MICE AND RATS 317 



active. They are able to fly noiselessly over fields and 

 through woods and to gather their prey quickly in their 

 hooked talons. Practically all the owls feed largely upon 

 field mice, and several of them, notably the Screech Owl 

 and the Long-eared Owl, find in them their chief source 

 of food. 



It has often happened that in certain regions the natural 

 enemies of the voles have been so persecuted as to become 

 scarce. When the checks upon their increase are thus re- 

 moved, the voles multiply with alarming rapidity and 

 become exceedingly destructive. When this occurs, the 

 hawks and owls from surrounding regions are attracted 

 to the infested locality, where they remain to feast upon 

 the mice. These raptorial birds are thus like a standing 

 army that nature moves from place to place to subdue in- 

 surrections. It is very foolish for man to wage war upon 

 this army ; he often has occasion to regret such persecution. 



Various other birds are also useful as destroyers of 

 meadow mice. Crows, ravens, and magpies feed upon them, 

 especially the young mice. Shrikes destroy great numbers. 

 Herons, bitterns, cranes, and gulls also feed upon them. 



Remedial Measures 



The ways in which farmers may aid in keeping meadow 

 mice below the danger line are many. One of the most 

 effective is by protecting the natural enemies of the voles. 

 Another is that of clean culture of the places where the 

 mice breed and the tillage of infested fields. Much help 

 can also be obtained from cats and dogs that are good 

 mousers and from close grazing by the larger domestic 

 animals. 



The chief means of direct destruction of the meadow 

 mice are traps and poisons. T^he so-called guillotine traps 



