COMMON MAMMALS OF WESTERN MONTANA. 



19 



cultivated areas, where each squirrel has but a few holes. Traps 

 should be visited at least once a day, in order both to secure the best 

 results and to avoid causing imprisoned animals unnecessary suffer- 

 ing. Figure 10 illustrates one way of handling a considerable num- 

 ber of traps. 



Ordinary Xo. 1 steel traps cost about $125 to $130 a thousand and 

 " jump " traps are slightly more expensive. 



FUMIGATION. 



Fumigation with carbon bisulphid is very effective when employed 

 early in the season while the ground is still damp. Dry ground 



Fig. 10.-— A convenient method of carrying 200 traps and stakes. 



rapidly absorbs the fumes. Crude carbon bisulphid suitable for this 

 purpose costs from 8 to 10 cents per pound in 50-pound carboys or 

 drums. Since it is a volatile liquid and rapidly loses strength on 

 exposure to the air, it should be kept in tightly corked bottles or cans. 



"When bisulphid is used to fumigate squirrel burrows, about a 

 tablespoonful should be poured on a piece of loosely rolled cotton 

 or other absorptive material and pushed as far as possible down the 

 burrow, the opening to which should then be immediately closed. 

 Every hole should be treated, and in case of outlying burrows a little 

 larger amount of the bisulphid should be used. As carbon bisulphid 

 is inflammable and the fumes highly explosive, it should never be 

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