2Q2 ECONOMIC MAMMALOGY 



or indirectly, to human life and property than any wild beast or venomous 

 serpent. It appropriates nearly everything that man eats, and drinks many 

 of his beverages. It follows him with its baleful influence from the cradle to 

 the grave. It destroys his poultry and molests his domesticated animals. It 

 has been known to attack and mutilate infants, sleepers, the sick, aged and 

 infirm. It is the forerunner of famine, pestilence and death. It carries the germs 

 of disease. It infects man's ships and habitations with the dreaded plague; 

 sets fire to his dwellings and ships, and ceases its ravages only when the house 

 burns or the ship sinks. As if not satisfied with pursuing him through life, it 

 follows him in death, desecrating and mutilating his mortal remains. 4 



The brown or Norway rat (Mus norvegicus) 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 disseminating infectious diseases. ... It de- 

 stroys grains when newly 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 eats. It carries dis- 

 ease 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 embankments by burrowing; destroys the farmers' 

 pigs, eggs and young poultry; eats the eggs and young of song and game 

 birds; and damages foundations, floors, doors and furnishings of dwellings. 5 



The brown house rats affect a "larger percentage of the population 

 than any other pest in existence." 6 Where sheltered and well fed, about 

 dwellings, stores, warehouses and farmyards, they multiply very rap- 

 idly. Their fecundity is discussed on a preceding page. The following 

 items are selected from Forbush's and Lantz' accounts of these rats: 

 There were 31,981 of them killed on a 2OOO-acre farm in 5 years; 

 38,000 killed on one Jamaican plantation in I year; 16,050 killed in a 

 French slaughterhouse in I month; 47,000 killed on 2 Georgian plan- 

 tations in the winter and spring of one year; 1700 killed in fumigating 

 i ship in London; 103,000 killed in Copenhagen in 18 weeks, and 

 71 1,797 in Stockholm in 7 years; during an outbreak of bubonic plague 

 in San Francisco 278,000 were captured in 4 months and it was esti- 

 mated that 500,000 more were poisoned; during a plague in India 

 12,000,000 were killed under a bounty or reward system; 28 were shot 

 in one cherry tree in a single afternoon ; in one crib they ruined enough 

 corn to have paid the taxes on a 4OO-acre farm ; on a 29-day voyage 



4 Forbush, Rats and rat riddance, Massachusetts Board of Agric., Economic 

 Biology, Bull. No. i, p. 7, 1915. 



6 Lantz, Methods of destroying rats, Farmers' Bull., No. 297, pp. 3-4, 1907; The 

 house rat: The most destructive animal in the world, Yearbook U. S. Dept. Agric. 

 for 1917, pp. 235-251. Hogarth, The rat, a world menace, 1929. 



6 Silver, How to get rid of rats, Farmers' Bull, No. 1303, p. 13, 1923. 



