COMMON MAMMALS OF WESTERN MONTANA. 9 



ground squirrels, chipmunks, and mice (fig. 1) were found from H 

 pints (7 cents' worth) of poisoned grain placed early in the season, 

 no dead animals were found from 5 bushels of the same preparations 

 put out after seeds and berries became abundant. 



COOPERATION IN RODENT POISONING. 



One of the most serious difficulties encountered in a campaign 

 against rodents or other pests lies in the refusal of a certain propor- 

 tion of the people in most communities to take part in such work. 

 The lands of these individuals then serve as breeding grounds from 

 which the surrounding areas are constantly restocked. For this 

 reason at the outset of such a campaign every effort should be made to 



Fig. 1. — Twenty-seven ground squirrels, chipmunks, and mice killed by 7 cents worth of 



poisoned grain. 



secure the cooperation of the entire community. It will greatly aid 

 in a campaign against rodents to have the poison bought in quantity 

 and the poisoned preparations made in large amounts at a central 

 point, whence the jieople taking part may secure it at cost. If each 

 individual made his own poisoned material, it would be a compli- 

 cated and unduly expensive process for small ranchers. The con- 

 venience of being able to get the prepared poison in small quantities 

 would greatly encourage small proprietors to take an active part in 

 the work. This is proved by the fact that every 3 T ear thousands of 

 dollars are spent for inferior and disproportionately expensive pro- 

 prietary poisons simply because they can be easily obtained. One 

 Montana orchard company last year bought 189 pounds of a certain 

 24208°— Bull. 184—12 2 



