86 RODENTS OF IOWA 



The clean mowing of grass lands and meadows, so that old grass 

 is not left over winter, also produces the same results. And finally, 

 the destruction of the natural enemies of the mice should be avoided 

 as largely as possible and not indulged in indiscriminately. 



Destruction of trees or nursery stock may be eliminated by using 

 a lime-sulphur wash, which while very effective is also very cheap. 

 To make the wash use twenty pounds unslaked lime, fifteen pounds 

 flowers of sulphur, and water to make forty-five to fifty gallons. 

 Boil in an iron, kettle at least an hour before application, which 

 should be made by means of a brush or in the form of a spray while 

 the mixture is yet warm. 



If trees have already been girdled by meadow mice, prevention 

 from decay and possible death is desirable. When these injured 

 places are subjected to the weather the bark dries and the trees die ; 

 while if the wounded places can be covered so as to exclude the air, 

 new bark will form and the injured parts will heal quickly. A 

 quick and efficient remedy is to mound up the trunks of the trees 

 with soil until the wound is covered, making due allowance for set- 

 tling. These mounds should remain in place all summer. Nursery 

 stock if only slightly injured by mice may in some cases be saved 

 by covering over the wounds with grafting wax or soil. The wounds 

 will heal over in one season. 



Trapping is a simple and effective method of destroying meadow 

 mice, but is not adapted to large or heavily intested areas since re- 

 sults are slow. However, if the infested area is small, such as a 

 lawn or garden where the number of mice is limited, this method 

 is efficient, and if -persisted in the mice may be practically extermin- 

 ated. Meadow mice will not enter cage traps, so the guillotine or 

 simple wire snap trap which kill instantly are preferable. They 

 are to be set with or without bait across the runways of the mice. 

 Cornmeal or oatmeal may be used successfully as a bait. 



The most satisfactory method of destroying meadow mice is 

 through the use of various baits poisoned with strychnin. To pre- 

 pare the poison dissolve a half ounce of strychnia sulphate in a 

 pint of boiling water and add a pint of thick syrup. Stir thor- 

 oughly. This quantity is sufficient to poison a half bushel of wheat 

 or corn, every grain of which should be thoroughly coated. If a 

 smaller amount is desired use the same proportions. The poisoned 

 bait should be placed under boards or other shelter so as to exclude 

 birds but admit mice. Pieces of drain tile about one and one-half 



