Rattlesnakes are native to the Americas from southern Canada to central Argentina, with the majority of species inhabiting arid regions. [7] The large majority of species live in the American Southwest and Mexico. Four species may be found east of the Mississippi River, and two in South America. In the United States, the state with the most types of rattlesnakes is Arizona, with 13. [8] a b Newman, Eric A.; Hartline, Peter H. (March 1982). "The Infrared "Vision" of Snakes". Scientific American. 246 (3): 116–127. Bibcode: 1982SciAm.246c.116N. doi: 10.1038/scientificamerican0382-116. Rattlesnake fangs are connected by venom ducts to large venom glands near the outer edge of the upper jaw, towards the rear of the head. When the rattlesnake bites, muscles on the sides of the venom glands contract to squeeze the venom through the ducts and into the fangs. When the fangs are not in use, they remain folded against the palate. [37] [38] The most probable ancestral area of rattlesnakes is the Sierra Madre Occidental region in Mexico. The most probable vegetation or habitat of the ancestral area appears to be pine-oak forests. [11] Prey [ edit ]

Furman, Jon (2007). Timber rattlesnakes in Vermont and New York: biology, history, and the fate of an endangered species. UPNE. ISBN 978-1-58465-656-2. Bryan Hughes (March 2, 2019). "Are rattlesnakes evolving to rattle less, or losing their rattles?". Rattlesnake Solutions.

Adams, Clark E. & Thomas, John K. (2008). Texas Rattlesnake Roundups. Texas A&M University Press. p.23. ISBN 978-1-60344-035-6. a b Luch, Andreas, ed. (2010). Molecular, Clinical and Environmental Toxicology. Vol.2. Springer. p.267. ISBN 978-3-7643-8337-4. Klauber, Laurence M. & Greene, Harry W. (1997). Rattlesnakes: their habits, life histories, and influence on mankind. University of California Press. ISBN 978-0-520-21056-1. Dogs are most commonly bitten on the front legs and head. Horses generally receive bites on the muzzle, and cattle on their tongues and muzzles. If a domesticated animal is bitten, the hair around the bite should be removed so the wound can be clearly seen. The crotaline Fab antivenom has been shown to be effective in the treatment of canine rattlesnake bites. Symptoms include swelling, slight bleeding, sensitivity, shaking, and anxiety. [50] In human culture [ edit ] Spirituality [ edit ] Stone sculptures of feathered serpents on display at the National Museum of Anthropology in Mexico City Indigenous Americans [ edit ]

Females secrete small amounts of sex pheromones, which leave a trail the males follow using their tongues and Jacobson's organs as guides. [70] Once a receptive female has been located, the male often spends several days following her around (a behavior not common outside of the mating season), frequently touching and rubbing her in an attempt to stimulate her. [71] [72] In the United States, more than 15,000 domesticated animals are bitten by snakes each year. Rattlesnake envenomations account for 80% of the deadly incidents. [102] Flaubert, Laurence M. (1997). Rattlesnakes: Their Habits, Life Histories, and Influence on Mankind. Vol.1. University of California Press. pp.384–389. ISBN 978-0520210561.

Rattlesnakes tend to avoid developed areas, preferring undisturbed, natural habitats. Rapid habitat destruction by humans, mass killings during events such as rattlesnake round-ups, and deliberate extermination campaigns all pose threats to rattlesnake populations in many areas. Several species, such as the timber rattlesnake, massasauga, and canebrake rattlesnake, are listed as threatened or endangered in many U.S. states. [83]