The number of rattles or buttons increases each time these snakes shed their skin. Because of this you can only approximate the age of rattlesnakes by the number of buttons on the tail. The females mate in March to May and in the early fall they give birth to live young. The young are able to fend for themselves and no parental care is given by the mother. In the winter these snakes will hibernate together in prairie dog burrows or rocky crevices.
Rattlesnakes are pit vipers.
They use specialized organs to detect heat. These pits, found below and in front of the eye, are placed at different positions on either side of the snake's head. This makes it possible for the snakes to line up their prey in total darkness. The fangs are covered by a protective sheath of tissue, and are normally folded back against the roof of the mouth. Rattlesnake fangs are hollow and are connected to a venom gland which lies behind the eye.