SCIURID^ 67 



in each squirrel hole; In a few days repeat the dose in all holes 

 that appear to be still used. Some Ground-Squirrels get cautious 

 Mid do not eat enough to kill them. These may perhaps be dis- 

 posed of by the use of bisulphide of carbon, which is fairly ef- 

 fective, and nearly as cheap as poisoned grain. The crude bisul- 

 phide is best as well as cheapest for this purpose. Its vapor 

 is heavier than air and flows down the burrow, replacing air, and 

 killing by suffocation. About a tablespoonful should be put on 

 a bunch of rags or dry balls of horse manure and placed in each 

 entrance to the burrow. It is best to close the mouth of the 

 burrow. Coal oil fumes are successful if the burrow is not too 

 large; use the coal oil in the same manner as the bisulphide of 

 carbon. It is the cheapest of all methods but not always success- 

 ful as the fumes are not as strong. 



Filling the burrows with the smoke of straw and sulphur 

 by using some of the patent smokers does well if the work is 

 done thoroughly, but it is rather slow work on a large scale. 

 Strychnine may be put on bits of apples, potatoes, etc., melon rind 

 being particularly useful. Trapping with No. o steel traps is 

 effective in a small place. The trap may be placed in the mouth 

 of the burrow and lightly covered with dust or left bare. Grain 

 or fresh meat may be used as bait, but if the trap is well located 

 in the mouth of the burrow bait is scarcely necessary. Stake the 

 traps well. Shooting may be the best method in some places. 

 Often it is necessary to use one of these methods after another to 

 get rid of the last squirrel, which may be exceptionally located,, 

 or unusually shrewd, but perserverance will conquer in the end 

 unless ones place joins land that cannot be cleared. 



The common note of the California Ground-Squirrel is a 

 single loud whistle, short, repeated at intervals. When cornered 

 in a rockpile or similar place they utter an angry chirring sound. 

 Their sight and hearing are good. They do not hibernate, but 

 in cold weather they remain in their burrows several days at a 

 time, but a warm spell soon brings them out. The number of 

 young at a birth is five to ten; they are born from the middle of 

 April to the first or middle of June, according to locality. 



