Every research study conducted over the past 20 years has shown that whitetail bucks make and check scrapes mostly at night. We have always naturally figured the deer do it for the safety factor—cover of darkness to avoid pressure—but one of the country’s foremost researchers has a different take.
The University of Georgia’s Dr. Karl Miller believes it’s more difficult for bucks to see and sort out other bucks (and does) at night than it is in daylight. So in the dark, bucks are drawn to scrapes–the ultimate scent-posts in late October and November–to keep tabs on and interact with other deer in the area. Miller says that trail camera photos and videos taken at scrapes show bucks sniffing each other’s tarsal glands more at night than during the day, another indicator that whitetails rely heavily on sense of smell in the dark to keep tabs on one another.
Interesting stuff. Maybe that explains why I have much more luck hunting rublines and crossing routes than scrapes.