The lore I have heard says that the cats are less successful hunting in the dark of the moon so more likely to hit the bait. I can neither confirm nor deny that, although I hunted at that time and they did hit the bait (just not until after dark). On the other hand, where it is legal it would be easier to see to shoot one in the light of a full moon. We sat until I could not see the tree with my naked eye some nights.