JUN 8 13U? 



METHODS OF DESTROYING RATS. 



INTRODUCTION. 



The brown or Norway rat {Mus 7iorvegicus) is the worst mammal 

 pest in the United States, the losses from its depredations amounting 

 to many millions of dollars yearly — to more, indeed, than the losses 

 from all other injurious mammals combined." In addition to its 

 destructive habits, this rat is now known to be an active agent in dis- 

 seminating infectious diseases, a fact wdiich renders measures for its 

 destruction doubly important. 



Introduced into America about the year 1775, the brown rat has 

 supplanted and nearly exterminated its less robust relative, the black 

 rat, and despite the incessant w^arfare of man has extended its range 

 and steadily increased in numbers. Its dominance is due to its great 

 fecundity and its ability to adapt itself to all sorts of conditions. It 

 breeds three or four times a year and produces from 6 to 12, and even 

 more, young at a litter. Young females breed when only 4 or 5 

 months old. The species is practically omniverous, feeding upon 

 all kinds of animal and vegetable matter. It makes its home in the 

 open field, the hedge row, and the river bank, as well as in stone walls, 

 piers, and all kinds of buildings. It destroys grains when newl}^ 

 planted, while growing, and in the shock, stack, mow, crib, granary, 

 mill, elevator, or ship's hold, and also in the bin and feed trough. It 

 invades store and warehouse and destroys fur, laces, silks, carpets, 

 leather goods, and groceries. It attacks fruits, vegetables, and meats 

 in the markets, and destroys by pollution ten times as much as it 

 actually eats. It carries disease germs from house to house and 

 bubonic plague from city to city. It causes disastrous conflagrations ; 

 floods houses by gnawing lead water pipes; ruins artificial ponds and 



O' Several species of rats are known as " house rats," including the black rat 

 {Mus rattus), the roof rat (Mus alexandrimis) , and the brown rat (Mus norve- 

 giciis). Of these, the last is the commonest and most widespread in this coun- 

 try. Not one of these species is a native, but all were imported from the Old 

 World. As their habits in general are similar, the instructions given in the 

 bulletin apply alike to all. 



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