BUREAU OF BIOLOGICAL SURVEY. 433 



poisoning or fumigating methods which would be effective in destroy- 

 ing these animals. 



In the Northwestern States woodchucks did considerable damage to 

 alfalfa and clover crops adjacent to the rocky ridges amid which 

 they live. The most extensive campaign against them was conducted 

 in Okanogan County, Wash., but some work was also done in Doug- 

 las, Grant, Kittitas, and Yakima Counties in the same State. It is 

 estimated that about 19,000 woodchucks were killed there, affording 

 protection to nearly 10,000 acres of crops and resulting in a substan- 

 tial saving. 



HOUSE RATS AND MICE. 



The bureau continued to furnish information through bulletins 

 and special articles on the destructiveness of house rats and mice, 

 the danger to health involved in their presence, and the practical 

 methods possible for their control. This information has been very 

 widely used by magazines, farm journals, and newspapers, and by 

 educational workers and public-spirited citizens in bringing to the 

 attention of individuals and communities the importance of applying 

 direct, vigorous measures for the eradication of these pests. Two 

 specialists of the bureau have been engaged during a large part of 

 the year in demonstrating control measures through the extension 

 services of the agricultural colleges and in assisting with the 

 organization of antirat campaigns in States east of the Mississippi 

 River, The entire force of rodent-control specialists employed by 

 the bureau in States west of the Mississippi has also cooperated in a 

 similar way in arousing interest in this important undertaking and 

 aiding in the organization and conduct of campaigns looking to the 

 eradication of these animals. In this way practically nation-wide 

 attention has been given to the matter of getting rid of rats, and 

 greater repugnance is being manifested to the presence of these pests 

 and an intolerance of the waste due to their depredations. 



Effort toward rat riddance has assumed larger proportions and 

 more definiteness of procedure. It is coming to be recognized that 

 the intelligent and persistent application of a few simple measures 

 will serve to rid a farm or a community of rats. Experience has shown 

 that rats can not long survive a concerted arid sustained campaign 

 against them. During the year the bureau has given particular atten- 

 tion to the working out of detailed plans of organization for use in 

 large-scale operations. Looking to the permanent elimination of the 

 rat pest, emphasis has been placed on the following features : Eat- 

 proof construction or repair of buildings ; the closing of all open- 

 ings which provide entrance for rats, including the screening of 

 basement windows; prompt disposal of garbage and elimination of 

 piles of trash and refuse where rats find food or harborage; the 

 poisoning of rats with barium carbonate in barns, granaries, ware- 

 houses, and other buildings in which the use of poison is practicable ; 

 systematic trapping where for any reason the use of poison is in- 

 advisable; the fumigation of rat burrows with carbon bisulphide 

 or hydrocyanic-acid gas; the use of effective rat dogs; and the organi- 

 zation of '^ community rat-killing drives. The plans of procedure 

 which are being followed involve educational effort to arouse the 

 public to a definite realization of the damage and danger involved 



