You'll get mixed comments and thoughts on this topic. Its a good question but Im not 100% convinced either way on. I would tend to think that on clear nights just the extra light may make them move later in the evening but like I said, no ones ever convinced me 100% as Ive seen deer not move one night and be allout inthe fields early right during a full moon phase.Others say its more than the moon's bright light and more about the lunar phases and such. When you find out please let me know