Pre-scenting is very effective... I've fed in the day time with no problems, I'm not implying that one works better than the other, I just choose to feed at night.
As for the light, to the best of my knowledge they spend the daylight hours in borrows, etc... coming out after dark to feed. I believe they "know" when it's dark... like they "know" the seasons are changing...
Maybe someone else will chime with more info?