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 tothe ball of cotton, when, from 
all appearances, the task was givenup. 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 yetcompact. 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. 
