438 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1920. 



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It is most encouraging, therefore, that it has proved possible to 

 make practical use of birds in destroying pests. Certain birds of 

 prey have been used in granaries and other storage rooms to clear 

 them of rats and mice, and small insectivorous birds have done good 

 service in greenhouses. The beneficial results of attracting birds to 

 farms and gardens are striking. They indicate, moreover, that even 

 greater results may be expected when more organized and widespread 

 efforts are made to increase the number of birds. 



