Some 30 million white-tailed deer make their home in the United States. Deer are the most highly studied mammals in the world, but does the typical homeowner with deer in the yard know how long deer can live? When they sleep? How many babies a doe can have each year? Enter the hidden world of white-tailed deer outfitted with night-vision cameras and GPS tracking equipment to see them not as common creatures, but as intelligent, affectionate family members.