R.D. Kirkpatrick 1964 Mus musculus Sand Island, Johnston Atoll, Pacific Oct. 11 PM I baited and set the 25 19 traps on the grid. Six mice were seen and at least 3 mice were in traps by the time I finished setting all the traps. Oct. 8:30 A.M. Had 17 mice, including 20 an unmarked one, in traps. 10 A.M. Used 23 traps to expand grid to 70' X 30'. Trap #'s 26 through 48 were set at 10' intervals whereas traps 1-25 were left in their old positions with 5' intervals. ↑ N 35 36 37 38 39 40 41 42 34 33 32 25 24 23 22 21 44 43 16 17 18 19 20 29 30 31 15 14 13 12 11 45 46 6 7 8 9 10 28 27 26 5 4 3 2 1 48 47 The grid now includes 2,100 sq. ft. of area. 3:30 P.M. 21 dropping boards were cut from cardboard and