192 ANIMAL COMPETITORS 



hasten the end. Experiments with similar or- 

 ganisms have been reported successful since in 

 Eussia and in France; but none of the like at- 

 tempts made during the mouse-plague in Ne- 

 vada in 1908 had an appreciable effect. 

 As Mr. Lantz says: 



"The destruction of noxious mammals is a more 

 complicated problem than that of insect destruction. 

 The farmer who fights these higher forms deals 

 with instincts and intelligence well adapted to cope 

 with his own in the struggle for existence. It is 

 not enough that he place poisoned food or traps 

 in the way of the creatures he desires to destroy; 

 he must make the baits attractive and allay the 

 natural suspicion of the animals by ridding traps 

 of all. suggestion of their real nature. He must 

 know the traits of the animals and take advantage 

 of any habit that will enable him to circumvent and 

 destroy them." 



Furthermore : 



"In warfare against any rodent pest little per- 

 manent good can be accomplished except by coop- 

 erative effort. Although it always pays the indi- 

 vidual farmer or fruit grower to exterminate pocket- 

 gophers from his own lands, yet if he can not se- 

 cure cooperation of the whole community he must 

 constantly guard against a return of the pests and be 

 ever ready to renew offensive operations against them. 



