Rattlesnakes are large, venomous snakes that are found throughout North and South America. The greatest concentration of them is in the Southwestern United States and in Northern Mexico. Arizona is home to 13 species of rattler, more than any other state. The most distinctive feature that these species share is the rattle.
Rattlesnakes also hiss, a second element of its warning posture that is often overlooked and overshadowed by its rattle, writes Laurence Monroe Klauber in “Rattlesnakes: Their Habits, Life Histories, and Influence on Mankind” (University of California Press, 1997). Viernum said the behavior “is similar to a cat hissing when threatened by a dog. In rattlesnakes, hissing and rattling their tails both serve as warning signals.
Rattlesnakes can range from one to eight feet, depending on the species (the big one is the eastern diamondback), according to the National Wildlife Federation. They are thick-bodied snakes with keeled (ridged) scales in a variety of colors and patterns. Most species are patterned with dark diamonds, rhombuses or hexagons on a lighter background. These adaptable serpents can thrive in a variety of environments. They are most abundant in the desert sands of the Southwest, but they also like grasslands, scrub brush and rocky hills. They can be found in the swamplands of the Southeastern United States and in the meadows of the Northeast. These snakes can handle high elevation and are found everywhere from sea level to 11,000 feet (3,353 m), according to the San Diego Zoo.