MOUSE PLAGUES, THEIR CONTROL AND PREVENTION. 



By Stanley E. Piper, 

 Assistant, Biological Survey. 



INTRODUCTION. 



Swarms of mice devastating the fields have been seen by very few 

 American farmers, but such scourges are among the oldest and most 

 disastrous known in history. Regarded with wonder and supersti- 

 tious awe in early times, and still looked upon in some countries as 

 miraculous, outbreaks of field mice are fraught with such dire con- 

 sequences to agriculture as to have earned the name of plagues. In 

 Europe and Asia mice have often almost completely destroyed crops 

 over areas varying in extent from thousands of acres to whole 

 provinces. Practically all vegetation suffers from their attacks. 

 Pasturage, hay, alfalfa, clover, grain, whether growing or stacked, 

 vineyards, shrubbery, and even forest trees have been destroyed. 

 As an example, Lenz thus describes a plague of mice in the years 

 1872-73 : 



In the rich corn lands of lower Saxony, Thiiringia, and Hesse they [mice] 

 abounded to a fearful extent. Half the harvest was destroyed — hundreds of 

 thousands of acres were left unfilled — and thousands of pounds were spent on 

 their destruction. Agricultural societies and Governments were implored to 

 seek ways and means of staying the plague. 



The extraordinary and rapid increase of a species until its numbers 

 assume the proportions of a plague is rare among mammals. Such 

 increase is most frequent among the several species of short-tailed 

 field mice and the lemmings. These animals, indeed, through their 

 great fecundity, are liable to break out periodically in vast numbers. 

 When they have increased excessively, some species migrate in large 

 bodies, travel long distances, and devastate the vegetation in their 

 path. Other species, however, do not perform such marked migra- 

 tions, but their excessive multiplication results in local and even more 

 serious damage. Gregarious by nature, the vast bodies they form 

 gradually extend from exhausted to fresh areas, until at length large 

 districts have been overrun and laid waste. 



A recent scourge in the United States lends more than usual inter- 

 est to the subject, especially since the mice responsible are closely 



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