Rattlesnakes are easily recognized poisonous snakes with a rattle at the end of their tails. As members of the pit viper group, rattlesnakes use their powerful venom to subdue their victims. This venom stops blood clotting and destroys internal tissues, quickly killing animals of all kinds, even humans when antivenom is not available. The most dangerous snake in this family is the Mojave rattlesnake, one with neurotoxin in its venom.

 

6 Rattlesnake Facts

• Although their venom can seriously injure or kill humans, rattlesnakes prefer to avoid any human contact

• These snakes can control how much venom they use when they bite

• Rattlesnakes are the newest and most evolved of all snake types

• Rattlers also make a hissing sound like a cat to warn predators to stay away

• Rattlesnakes range in size from one foot long to over eight feet

• Rattlesnakes eat only one meal every two to three weeks.

Rattlesnake Scientific Name

Rattlesnakes are members of the Reptilia class and Viperidae family, specifically of the subfamily Crotalinae, the pit vipers. The name “rattlesnake” comes from the Middle English verb “rattle,” a word formed from the sound of loose objects hitting each other. The second half of the viper’s name is simply the Middle English word “snake,” meaning “serpent reptile.”

Types of Rattlesnakes

There are over 30 rattlesnake species; most of them fit within the genus Crotalus, the smaller Massasauga and pygmy rattlesnakes are in the genus Sistrurus.

Crotalus genus rattlesnakes listed according to scientific name:

• Eastern Diamondback Rattlesnake (Crotalus adamanteus)
• Queretaran dusky rattlesnake (C. aquilus)
• Western Diamondback Rattlesnake (Crotalus atrox)
• Mexican west coast rattlesnake (C. basiliscus)
• Santa Catalina rattlesnake (C. catalinensis)
• Arizona black rattlesnake (C. cerberus)
• Sidewinder (C. cerastes)
• Midget faded rattlesnake (C. concolor)
• Neotropical rattlesnake (C. durissus)
• Baja rattlesnake (C. enyo)
• Southern Pacific Rattlesnake (C. helleri)
• Timber rattlesnake/canebrake (C. horridus)
• Mexican small-headed rattlesnake (C. intermedius)
• Autlan rattlesnake (C. lannomi)
• Rock rattlesnake (C. lepidus)
• Speckled rattlesnake (C. mitchelli)
• Black-tailed rattlesnake (C. molossus)
• Mexican lance-headed rattlesnake (C. polystictus)
• Twin-spotted rattlesnake (C. pricei)
• Red Diamondback Rattlesnake (Crotalus ruber) has three recognized subspecies, Cedros Island red diamond rattlesnake (C. r. exsul), San Lucan red diamond rattlesnake (C. r. lucasensis), and the red diamond rattlesnake (C. r. ruber).
• Mohave rattlesnake (C. scutulatus)
• Long-tailed rattlesnake (C. stejnegeri)
• Tiger rattlesnake (C. tigris)
• Tortuga Island rattlesnake (C. tortugensis)
• Cross-banded mountain rattlesnake (C. transversis)
• Aruba Island rattlesnake (C. unicolor)
• Prairie rattlesnake (C. viridis)
• Ridge-nosed rattlesnake (C. willardi)

Sistrurus genus rattlesnakes:

• Pygmy rattlesnake (S. miliarius)
• Massasauga rattlesnake (S. catenatus)
  
  

Rattlesnake Appearance & Behavior

There are 36 species of rattlesnakes and 65 to 70 subspecies. All of these are native to the Americas, from southern Canada to Argentina.



Among the largest rattlesnakes are those living in the Eastern half of the United States. The timber rattlesnake typically ranges from 2.5 to five feet long, although some are recorded at as much as seven feet in length. The eastern diamondback can grow up to eight feet in length and weighs as much as 10 pounds, as the largest in its species. One of the smallest rattlesnakes is the pygmy of Florida. The pygmy averages one to 1.5 feet in length, about the same length as a domestic cat.



Rattlesnakes have thick bodies with heavily ridged scales. Their coloration varies according to their habitat. But most have dark patterns of diamonds or other geometric shapes on a lighter colored background.



At the end of their tails you can see a distinctive rattle made up of hollow keratin chambers. These chambers knock together when a rattlesnake shakes its tail, making the rattling noise. The rattle gains a new segment each time the snake sheds its skin. But rattles often break due to damage caused as part of daily living in their environment.



Besides their rattler and a distinctive patterned design, rattlesnakes also have a triangular head and hinged fangs. Their eyes have cat-like vertical pupils.



Although rattlesnakes are aggressive, they avoid human contact. They only attack humans with their powerful fangs and venom when provoked. If you corner or startle a rattlesnake, you will first hear their rattling sound as they shake their tail to warn you.



These snakes also hiss like a cat. The hissing sound comes from deep in their throats. At the same time, you can sometimes see their body swell and deflate as they take in and let out air to make the hissing sound.



When a rattlesnake feels defensive, it coils into a tight circle. They raise their head high to prepare to strike. They can strike out at predators at a distance as far away as one-third of the snake’s overall body length.

Rattlesnakes vs. Other Snake Species

Rattlesnakes are often confused with other snake species that live in the same habitats. Kingsnakes are often found in the same habitats as rattlesnakes but are nonvenomous. In fact, kingsnakes will actually hunt rattlesnakes and use constriction to disable rattlesnakes before they can attack with their venomous bites.

Rattlesnake Habitat

Among all rattlesnake locations, the greatest concentration of these snakes live in the southwestern states of the U.S. and northern part of Mexico. Arizona is home to the most types of rattlesnakes, with 13 calling that U.S. state home. Many rattlesnake varieties live in California as well.



More rattlesnakes live in the Southwest’s desert sands and dry climate than elsewhere. But many subspecies thrive in other climates and environments. They do well in grassy regions, rocky hills, swamplands, meadows, brushy areas and even as high as 11,000 feet above sea level.



Rattlesnakes live in dens within rocky crevices. During winter in colder climates, they hibernate in their dens. For snakes, this period of rest is called brumation.



Generations of the same snake family often re-use their dens, sometimes for longer than 100 years. When they leave the den during daytime, the snakes sunbathe on warm rocks or out in the open. When the weather becomes extremely hot during summer, they sometimes shift their schedule for more nighttime activity.



Some rattlesnakes spend a lot of time in trees. They can slither up a tree and reach heights of 80 feet or more.



The snakes’ body pattern and colors vary according to their environment. These colors and patterns serve as camouflage to protect them from predators.

 

Rattlesnake Diet

Rattlesnakes eat a wide variety of small mammals. They prefer rats, mice, birds, rabbits and other small creatures like lizards and frogs. Rattlesnakes track their prey using a keen sense of smell. When not tracking, they lie in wait until attractive prey passes by. These snakes do not need more than one meal every few weeks in adulthood.



Finding prey is not difficult for a rattlesnake. They have very keen eyesight and a strong sense of smell using both their nostrils and their flicking tongues. They also have heat-sensing pits near the tip of their nose. These pits sense warm-blooded animals in the environment. Despite these well-developed senses that help them hunt for prey, rattlesnakes have terrible hearing. But they can sense vibrations in the ground, such as for a human or animal walking nearby.



To capture their prey, rattlesnakes strike fast and inject their venom into the animal using their powerful fangs. The venom immediately paralyzes the prey. It only takes half a second for the snake to strike and render their food immobile. Then, the snake swallows the food whole and retreats to their den or another safe and quiet place to digest their meal. Digestion takes several days and makes the rattler sluggish.



Although about 8,000 rattlesnakes bite humans each year, they do not attack humans as prey. This is defensive, only. Of these bitten people, only about five die in a given year. Proper attention must be given to pets that fall victim to rattlesnake bites.

 

Rattlesnake Predators & Threats

One of the biggest predators of rattlesnakes in the wild is the king snake. Black snakes also attack and eat rattlers. One popular belief is that bullsnakes will eat rattlesnakes, but this is purely a myth.

Owls, eagles and hawks enjoy making a rattlesnake their meal. Strong predatory birds like these swoop down from flight to attack and carry the snake away in their talons. Wild breeds of cats, foxes, coyotes and even turkeys like to eat rattlesnake meat, too.



Big animals and humans tend to avoid rattlesnakes. The snakes’ telltale hiss and tail rattle scare off bigger predators like these. But hoofed animals like bison will stomp a rattler to death, if necessary and to avoid being attacked, themselves. Although the snake’s venomous bite can kill humans, many people risk capturing rattlers for food. Some diners enjoy the taste of rattlesnake meat. Others use the reptiles’ skins to make boots, shoes, belts, handbags and other material goods.



Another threat to the rattlesnake is urban development. Development by humans takes over the snake’s habitat and encroaches on their hunting grounds. One of the biggest killers of rattlesnakes is traffic. Many are run over by cars each year.



Several species of rattlesnakes are listed as endangered or vulnerable in the U.S. These include the timber rattlesnake, canebrake rattlesnake and massasauga rattlesnake.

How to Avoid Rattlesnakes in their Habitat

Rattlesnakes range all the way from Canada to Argentina, so if you’re the outdoors-type, you may encounter a rattlesnake across much of not only the United States, but the Americas. If hiking, the best advice for avoiding rattlesnakes is to stay on trails. Most encounters where rattlesnakes bite occur because they’re startled. If you do come close to one, avoid sudden movements and back away. Rattlesnakes are not aggressive and will not pursue.

Rattlesnake Reproduction, Babies, and Lifespan

Female rattlesnakes only reproduce once every three years. This mating usually takes place during summer or fall. But some species mate in spring or both spring and fall.



To find an appropriate mate, females secrete sex pheromones. This leaves a scent trail that the males follow using their advanced sense of smell. When the male locates the female, he follows her for several days. Over the course of this time, he often touches or rubs her to make his intention known.



Sometimes males compete for females by fighting each other. The male snakes do a “combat dance” that involves wrapping their bodies around each other. Large males easily scare smaller males away.



Rattlesnakes do not lay eggs. Instead, the female produces eggs in her ovaries like humans. But they release multiple eggs in a continuous chain into their oviduct, a tube. The male sperm fertilizes these eggs. Fertilized eggs usually gestate in the female for 167 days. When the babies are at full term, the eggs hatch inside the female. Then, the female gives birth to about 10 to 20 live baby snakes.



Instead of a rattle, baby rattlesnakes are born with a “pre-button.” When the baby starts shedding its skin, their rattle starts forming and grows bigger with each skin shedding. Baby rattlers are more aggressive than adults and have venom in their fangs.



Rattlesnakes live in the wild for a range of 10 to 25 years.

 

Rattlesnake Population

Rattlesnake populations are hearty across the United States and listed as “stable” in numbers. That is, for all sub-species except the timber rattlesnake. The timber rattler once lived in 31 states. Now, it is listed as endangered in Virginia, Connecticut, Ohio, Indiana, Massachusetts, New Hampshire, Minnesota, New Jersey and Vermont. The snakes no longer exist in Maine and Rhode Island. Massachusetts counts only 200 timber rattlesnakes left in the state.

View all 74 animals that start with R