R.D. Kirkpatrick 1964 Mus musculus Sand Island, Johnston Atoll, Pacific Nov. 9 A.M. 38 mice (including 5 4 unmarked ones) were caught on the grid. Nov. 8 A.M. 40 mice (including 4 unmarked 5 ones) were caught on the grid. 11 P.M. It was noted that mouse eyes reflect the light of a flash- light (which is characteristic of nocturnal animals). Nov. 8:30 A.M. 29 mice (including 3 6 unmarked ones) were caught on the grid. Nov. The traps were not set last night. 7 7:30 A.M. I set all the grid traps but did not bait them. 9:30 A.M. No Mus were in the traps. 11:30 A.M. " " " " "" 1:30 P.M. " " " " "" 3:30 P.M. " " " " "" 5:30 P.M. One Mus (marked) was in the traps. 7:30 P.M. 15 Mus (including 2 unmarked ones) were in the traps. Nov. 3:30 A.M. 33 Mus (including 5 8 unmarked ones) were in the unbaited traps.