The white-tailed deer, Odocoileus virginianus , was so named because the underside of its tail is covered with white hair, and when it runs it often holds its tail erect so that the white undersurface is visible. Whitetails belong to the Cervidae family which in North America includes the elk, moose, caribou and mule deer.
Cervids are split-hoofed mammals with no incisor teeth in the front of the upper jaw.
Adult male whitetails grow and shed a set of antlers each year. On rare occasions, does also grow antlers. Scientists have identified 30 subspecies of whitetails in Central and North America. Whitetails occur from southern Canada south through the United States and Mexico to Panama, but they are absent from most of Canada, Nevada and Utah. They occur commonly throughout Pennsylvania.