studied rodent-control methods for more than twenty yee.rs and in this period 

 it has developed the most scientific and selective poisons possible. Scien- 

 tific investigations conducted "oj the Bureau are bringing increasing knowledge 

 of the habits of economically injurious species and of their physiological 

 reaction to various baits. This has made it possible to use more and more 

 specific control methods and so to select, prepare, and expose poison baits 

 as not seriously to endanger animals other than those for which the oaits are 

 intended. riliien these scientific methods are carried out under direct super- 

 vision of trained personnel, the total number of beneficial species destroyed 

 is negligible. 



The Biological Survey is a conservation organization and will undertake 

 no work that will be detrimental to any species of animal not interfering too 

 greatly with the interests of man. Those conversant with actual conditions 

 in the range States realize that if agriculture is to survive, the control of 

 injurious rodents is as essential as is control of the corn borer, the chinch 

 bug, the boll weevil, the grasshopper, the coddling moth, and numerous other 

 agricultural pests. The Survey insists that in conducting work of this sort, 

 the most careful supervision by trained technicians must be given. All coop- 

 erating agencies recognize the necessity for such supervision, and as a result 

 a most worth-while program has been carried on during the past thr^e fiscal 

 years. The Biological Survey has entered into written cooperative understand- 

 ings with the various governmental agencies under which rodent-control activ- 

 ities have been conducted. These agreements place the responsibility for 

 technically supervising all rodent-control activities in the hands of the 

 Bureau, leaving the cooperating agencies responsible for administration. 



Control work Illustrated 



The illustrations or. the following pages tell better than would volumes 

 of written words, the story of rodent damage and of cooperative work to reduce 

 this damage. 



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