332 Bulletin 81 



We found that rolled barley was most effective. Excellent results were 

 obtained bj' making and applying bait according to the following formula, 

 recommended by the U. S. Biological Survey: 



DIRECTIONS FOR POISONING PRAIRIE-DOGS IN ARIZONA 



"Dissolve 1 ounce of strychnine sulphate in 13<2 pints of boiling water. 

 Add 1 heaping tablespoonful of gloss starch, previously mixed with a little 

 cold water, and boil until a clear paste is formed. Add 1 ounce of baking 

 soda and stir to a creamy mass. Add 1-12 ounce of saccharine and 34 

 pint of syrup and stir thoroughly. Pour over 13 quarts of rolled barley 

 and mix vi^ell until every grain is evenly coated. Allow to dry before 

 using. 



"In bushel quantities use, as above directed, 2j/2 ounces strychnine, 2^/2 

 ounces soda, 1-5 ounce saccharine, 1^4 ounces starch, 13^4 quarts boiling 

 water and ^ of a pint of sirup. 



"Scatter poison, when the natural food of the prairie-dog is scarce, 

 on clean, hard places near the holes, 1 quart to 50 holes. Do not put the 

 poisoned bait in the holes. 



"If powdered strychnine alkaloid is used, prepare the hot starch paste 

 first. Then sift strychnine and baking soda previously mixed thoroughly 

 together, into the hot starch paste, and stir to a creamy mass. Proceed as 

 in the above directions with sirup, saccharine, etc. 



"In some localities in Arizona where the natural prairie-dog foods 

 are abundant, success with poison has not always been obtained by the 

 usual methods. In such cases excellent results may be secured by placing 

 a very small quantity of clean rolled barley at each active hole and after 

 two days treat the areas with poisoned grain prepared as in the above 

 directions. 



Caution 



"All poison containers and all utensils used in the preparation of 

 poison should be kept plainly labeled and out of reach of children, irrespon- 

 sible persons, and livestock," 



When poisoned bait is used according to the above direction — that is, 

 about one small tablespoonful thrown down on hard earth near the hole, 

 thus scattering the bait, there is no danger of poisoning stock. 



In cases where it is desired that the prairie-dogs be killed off quickly 

 while the natural food is plentiful, or where a farmer has only a few 

 acres infested with prairie-dogs and does not care to use poisoned bait, 

 carbon bisulphide ("high-life") may be used. This generally kills all of 

 the animals with one application. It is more expensive to use than the 

 poisoned bait. The following directions are recommended by the U. S. 

 Biological Survey: 



"One ounce (two tablespoonfuls) of carbon bisulphide should be poured 

 on a small piece of cotton waste or other cheap absorbent material and 

 placed well down the hole. Close the hole immediatelv with dirt or sod. 



