In some, certainly not all, cases it is the angle the low beams are at coupled with the height of the vehicle. I work with guys that had it changed because they felt bad when people would flash highs

I missed that hot sauce one. Woo eee is right

An abstract from an article in the Journal of Environmental Studies in 2015:

"White-tailed deer are widely distributed in North America and for at least 10,000 years have been important to human beings for food, clothing, and tools. Market hunting and habitat changes in the 1800s caused a precipitous decline in the number of white-tailed deer in North America. Hunters acted to restore deer populations. By promoting and helping to enforce hunting regulations, trans-planting deer, and funding conservation and management programs, hunters were the primary rea-son deer populations grew during the 1900s from 500,000 to nearly 30 million. Today white-tailed deer are the most popular big game animal in North America and hunters continue to fund deer management and research. Hunters help wildlife agencies to manage white-tailed deer populations within ecological and cultural carrying capacity by harvesting deer. Thus, hunters, with their inter-est in viable deer populations, are integral to the conservation and management of white-tailed deer in North America."