278 FUMIGATION METHODS 



soil, a small quantity will suffice ; but if the burrow is 

 large, rather shallow, and with several openings lead- 

 ing to the surface, much more liquid will be required. 

 As a rule, a small wad of cotton ; wool, old rags, excel- 

 sior, even dry grass or a corn-cob, saturated with a 

 little less than one ounce of the liquid and heeled in 

 the holes, will do the work. A Nebraska farmer says 

 he uses dried balls of horse manure. They hold the 

 liquid well, are less expensive than cotton, and easily 

 obtained. 



On the Laramie Experiment Farm in Wyoming 

 ninety -six burrows were treated during the month of 

 July. The applications were, with few exceptions, 

 made in the evening. The next day the treated bur- 

 rows were visited, and in no instance had the earth 

 which had been used for plugging the opening been 

 disturbed. A second and third visit to these burrows 

 found them securely plugged. In two instances some 

 animal, presumably a ground squirrel, had made an 

 effort to dig open the burrow from the outside. The 

 opening extended only to the ball of cotton, when, from 

 all appearances, the task was given up. In forty -three 

 instances gophers (squirrels) were driven or seen going 

 into the burrows and treated at once. None of the 

 animals ever again saw daylight. 



It is best to perform the work in the evening, other- 

 wise some of the treated burrows will be dug open by 

 out-lying squirrels. The remedy can best be applied 

 in the spring, while the ground is yet compact. Where 

 the balls of dried horse-dung are used the cost is 

 reduced and the rounded masses carry the chemical 

 beyond the reach of the dirt used in closing the hole. 



