White-tailed deer are primarily herbivores, so they eat all sorts of plants, such as switch grass, American holly, ferns, aquatic plants and poison ivy. However, depending on what's available, white-tailed deer also eat alfalfa, nuts, grass or fungi.
White-tailed deer living in desert areas also eat cacti, and white-tailed deer living in eastern forests eat buds and twigs. In more populated areas, whitetails feed on plants grown by people, such as ornamental trees, crops and fruit trees. The white-tailed deer's diet also consists of evergreen trees in the winter, because of the low availability of foods. White-tailed deer are the smallest in the North American deer family and are nocturnal or crepuscular creatures, meaning they are only active in the dark or twilight.