It seems not unlikely, therefore, that during seasons of drought the banner-tailed kangaroo rat, where it is abundant on the grazing ranges of the Southwest, may be a factor of critical importance in relation to forage production and carrying capacity. It must be remembered, moreover, that the stored material consists largely of seeds, so that this loss is of greater importance than would be the case were it ordinary forage. Some of the range grasses of this region found in greatest quantity in the stored material depend in large part, under certain conditions, upon seed reproduction. Rehabilitation of a depleted range after severe drought and consequent close grazing and trampling is retarded by the heavy toll of seed taken by the kangaroo rats. CONTROL. Kangaroo rats may be easily eradicated by the use of the poisoned grain used for prairie-dog control by the Biological Survey and the University of Arizona Extension Service. This can be obtained by application to the State representative of the Biological Survey or to the local county agricultural agent, or may be mixed as follows: _Formula for poisoned bait._--Dissolve 1 ounce of strychnine sulphate in 1-1/2 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 1/2 ounce of glycerine and 1/4 pint of corn sirup and stir thoroughly. Pour over 16 quarts of rolled barley and mix well until every grain is evenly coated. Allow to dry before using. In bushel quantities use as above directed, 2 ounces of strychnine, 2 ounces of soda, 1 ounce of glycerin, 1-1/4 ounces of starch, 1-1/2 quarts of boiling water, and 5/8 pint of corn sirup. Scatter poison, when the natural food of the kangaroo rat is scarce, on clean hard places near the holes, 1 quart to 50 holes. If powdered strychnine alkaloid is used, prepare the hot starch paste first. Then sift strychnine and baking soda, previously thoroughly mixed, into the hot starch paste and stir to a creamy mass. Proceed as in the above directions with sirup, glycerin, etc. Use this poison within five days after mixing or retain in air-tight containers. _Caution._--All poison containers and all utensils used in the preparation of poison should be kept _plainly labeled_ and _out of reach of children_, irresponsible persons, and live stock. A spoonful of the poisoned grain scattered about the used entrances of a mound is sufficient, and prebaiting is not necessary, as with prairie dogs.