R.D. Kirkpatrick 1964 Mus musculus Sand Island, Johnston Atoll, Pacific Ocean Nov: A.M. A total of 35 mice (including 1 $10 unmarked ones) were trapped on the new grid. Two of the unmarked ones were destroyed because they were overheated in the traps and it was felt that they would not survive. One of the 2 was made into skin and skull RDK #396. 9:30 to 10 P.M. The 48 grid traps were set. Nov. 8:30 to 9 A.M. A total of 36 mice (including 2 seven unmarked ones) were found in the grid traps. These Mice will not use dropping boards or open ½-gallon milk cartons to defecate on or in. The only use made of them was incidental or accidental. The mice do use Wedgetail Shearwater burrows for cover as well as vegetation and debris on the ground since they are commonly observed, day as well as night, running into and out of the burrows constructed by birds. Nov. 8 to 8:30 A.M. A total of 37 mice 3 (including 7 unmarked ones) were found on the grid.