PHOENIX, AZ - DECEMBER 23: A massasauga rattlesnake lays in its enclosure on December 23, 2017 in the Phoenix zoo in Phoenix, Arizona. The massasauga used to be a fairly common snake in the central United States, but because of habitat loss and a common habit of killing rattlers, this shy snake is now very rare. (Photo by Andrew Lichtenstein/ Corbis via Getty Images)
