They hiss, they rattle, they bite. Rattlesnakes are one of the most feared snakes in North America, and it’s easy to see why: they have a venomous bite.
Rattlesnakes can be found in both North and South America, but the greatest concentration is in the southwestern U.S. and northern parts of Mexico. Arizona alone has more than 13 different species of the rattlesnake.
Table of Contents
Rattle and Hiss
If you live in the southwestern U.S., you know the distinct sound of a rattlesnake. And you probably grew up learning to respect and fear these slithering creatures. 
These pit vipers have a very distinctive rattle or buzz that warns predators to stay away.
So what makes a rattlesnake rattle? Keratin. Segments of keratin are clustered at the end of the snake’s tail. These segments fit loosely inside one another, and they knock against each other when the snake holds its tail upright and vibrates. This knocking action is what creates the buzzing sound rattlesnakes are known for.
Every time a rattlesnake sheds its snake skin, it adds another segment to its tail, or rattle. As these snakes age, parts of their rattle start to wear away and break off. That’s why some adult rattlers have no rattle.
Along with its rattle, these snakes also hiss to keep predators away. Most people never pay attention to the hissing. The rattling is all they need to turn and run the other way. To create that hissing sound, snakes forcefully expel air from the glottis in their throats. That forceful action causes the glottis to rattle and make a hissing.
Sometimes, the snake’s body expands when it hisses. Long story short: if you hear the rattling and hissing of a rattlesnake, stop and turn the other way.
6 Rattlesnake Description and Characteristics
1. Appearance and Size
Rattlesnakes have a distinct appearance, and their size can range from one to eight feet, depending on the species.
Rattles have thick bodies with ridged scales. Their colors and patterns vary, but are quite distinct. Most have dark diamond, rhombus or hexagon patterns on lighter backgrounds.
Rattlesnakes are usually black, olive, brown or gray in color. They camouflage into their surroundings to hide from predators in plain sight.
These snakes also share the characteristics of other pit vipers, including:
- Heat sensing pit
- Live births
- Hinged fangs
- Vertical pupils (i.e. cat eyes)
- Triangular head
Young rattlesnakes don’t have rattles, but they’re just as venomous as adults – which makes them just as dangerous.
2. Habitat
Rattlesnake are highly adaptable creatures, which means they can live in a variety of habitats. They can be found in both North and South America, but they’re most common in the southwestern U.S. and northern parts of Mexico.
Rattles prefer living in dry, desert-like conditions, but they can also be found in scrub brush, grasslands and even rocky hills.
In the southeast, they hang out in swamplands. In the northeast, they prefer meadows.
Rattles can be found in low or high elevations – even up to 11,000 feet above sea level.
3. Behavior and Habits
Rattlesnakes make dens inside rocky crevices, and spend their time here when they’re not hunting. Rattles that live in cold climates will hibernate in their dens during the harsh winter months.
Several generations of rattlesnakes will use the same den – sometimes for more than 100 years.
When they emerge from their dark holes, rattles will bask in the sun on rocks and out in open areas. No wonder they love to hang out in deserts.
Rattles aren’t exclusively nocturnal animals, but they prefer to hunt at night – especially in the hot summer.
4. Diet, Lifespan and Reproduction
Like other pit vipers, rattlesnakes are carnivorous creatures (meat eaters). They dine on lizards and rodents, but other small creatures are on the menu, too.
When stalking their prey, rattlers will wait until their meal comes along and strike at lightning fast speed – five-tenths of a second.
Rattlesnakes inject their venom when they strike, which paralyzes the victim. Once subdued, the snake will swallow its dinner whole. Some species of rattlers will wait until their prey is dead before eating it.
Digestion can take several days. All that eating leaves the snake feeling sluggish and tired, so it hides away until it starts feeling like its normal self again.
In the wild, rattlesnakes can live 10-25 years.
Rattlers mate in the warm spring and summer months, depending on the species. Males may fight each other to win the chance to mate.
Like other snakes, females excrete pheromones that leave a trail for males to follow. Once males find a female, they’ll spend days following her around, touching and rubbing her.
Females can store sperm in their bodies for months before the eggs are fertilized. Mom snakes only carry their young for three months before giving birth.
Rattlesnakes are ovoviviparous, meaning they carry their eggs inside their bodies until they’re ready to give birth. The heat from the snake’s body incubates the eggs.
A female rattlesnake will give live birth, with babies encased in a thin membrane. Babies puncture the membrane and go about their separate ways. Most moms give birth to about 10 babies at a time. Rattlers only give birth every two years.
5. Bite and Venom
Rattlesnakes may be venomous and have painful bites, but they really have no intention of hurting humans – unless they have to.
Many people get bit by a rattler because they accidentally stepped on one. If you’re hiking or walking a trail, please watch your step.
While rarely fatal, a rattlesnake’s bite is something to be feared – they can be dangerous. If you get to the doctor fast enough and get the proper antivenin, a rattlesnake’s bite won’t be too serious.
A rattler’s venom is very potent, and typically contains hemotoxins. In some species, their venom contains neurotoxins, which can cause:
- Muscle weakness
- Visio problems
- Speech problems
- Trouble swallowing and breathing
- Respiratory failure
Studies have found that hemotoxic venom is becoming less common, and more rattlers are evolving to have neurotoxic venom.
If left untreated, a bite can cause:
- Tissue and muscle damage (temporary or permanent)
- Loss of limbs
- Internal bleeding
Most people will experience extreme pain at the injection site.
Fatalities from rattlesnake bites are rare as long as they’re treated in a timely manner.
6. Classification/Taxonomy
Rattlesnakes are a type of pit viper and belong to the Viperidae family – the same family as copperheads and cottonmouths.
Rattlers are part of the Crotalus genus, which is related to the pygmy rattlesnake, and the subfamily Crotalinae.
【Read more about Cottonmouths】
Rattlesnake Species
There are 29 different species of rattlesnakes, which include:
1. Timber Rattlesnake
Also known as the banded rattlesnake and the canebrake rattlesnake, the timber rattlesnake is most commonly found in the northeastern U.S.
Timber rattlesnakes grow to be about 36-60 inches in length, and weigh between one and three pounds. They usually have black or dark brown crossbands on a gray or yellow-brown background. These crossbands may be V-shaped or M-shaped.
Timbers are found in the eastern U.S. from Minnesota down to New Hampshire, Texas and northern Florida.
These snakes are considered some of the most dangerous in North America simply because they have long fangs and high venom yield. Thankfully, these creatures have a pretty mild disposition.
2. Eastern Diamondback
Eastern diamondbacks are the biggest venomous snakes in North America. Some of them can grow to be eight feet long and weigh up to ten pounds.
This species of rattlesnake typically lives in sandy woodlands, pine flatwoods and along coastal scrub habitats. These snakes can be found from North Carolina down to Florida and even west into Louisiana.
The eastern diamondback rattlesnake has light-centered black diamond patterns with yellow borders. They’re among the most striking snakes in North America.
3. Western Diamondback
The western diamondback rattlesnake lives in the southwestern U.S. and Mexico. It’s believed that this species is responsible for most rattlesnake bite fatalities in northern Mexico and for most snakebites in the United States.
These snakes can grow to be four feet in length, with males being larger than females. Western diamondbacks have dusty gray-brown patterns. They typically have 24-25 dorsal blotches that are brown in color.
This species of rattlesnake can be found in the western U.S. from Arkansas to California and Mexico. These snakes are excellent climbers, and they’re solitary creatures – except when mating.
4. Mojave Rattlesnake
The Mojave rattlesnake is a highly venomous snake found in the deserts of central Mexico and southwestern U.S. This legendary snake pit has an extremely potent neurotoxic-hemotoxic venom, and it’s known as one of the most potent rattlesnakes in the world. The Mojave rattlesnake grows to be about three feet in length and comes in a variety of colors, from brown to pale green.
These snakes are found in desert areas of southwestern United States and parts of Mexico, including Southern California, Utah, Arizona, Nevada, New Mexico and western Texas. The Mojave rattlesnake’s venom is so potent, it’s considered the most deadly rattlesnake – and even more deadly than the Mozambique spitting cobra. Despite its dangerous venom, your chances of survival are great if you get medical attention right away.
5. Sidewinder
The sidewinder, also known as the horned rattlesnake, is also found in the deserts the United States and Mexico. This species is smaller than most other rattlesnakes. They average between 17″ and 30″ in length. Females are larger than males.
Sidewinders have lighter colors of cream, yellow-brown, buff, ash gray or pink. They can be found in eastern California, western Arizona and southwest Utah.
6. Pigmy Rattlesnake
The pigmy rattlesnake is smaller in size – about 16-24 inches long. They typically have dark blotches on a light background, which may merge and look like stripes on the head.
Pigmy rattlesnakes can be found in southeastern United States from North Carolina down to Florida, eastern Texas and Oklahoma. They prefer to live in floodplains, flatwoods, forests, sandhills and near water.
7. Massasauga Rattlesnake
Common in Midwestern North America, the Massasauga rattlesnake’s habitat runs from southern Ontario to northern Mexico and parts of the U.S. in between.
This species grows to be between 24″ and 30″ long with grey and tan patterns and black/brown blotches along the center of its back.
The Massasauga has cytotoxic venom, which means it destroys tissue. They also have digestive enzymes that prevent blood clotting and disrupt blood flow.
These snakes are shy and prefer to avoid humans. Most bites occur because humans try to pick them up or accidentally stepped on them.
8. Prairie Rattlesnake
Found in southwestern Canada, western U.S. and northern Mexico, the prairie rattlesnake can grow to be nearly five feet long.
Prairie rattlers are typically light-colored with patches of dark brown. They may have a color band at the back of their eyes.
9. Southern Pacific Rattlesnake
The Southern Pacific rattlesnake is sometimes called the black diamond rattlesnake. These snakes are commonly found in southwestern California and down into Baja California, Mexico.
Adult snakes are typically 24-55 inches long with dark brown blotches on a yellow-brown, gray-brown or light brown background.
Like the Mojave rattlesnake, the Southern Pacific has highly toxic venom that attacks nerve endings.
10. Aruba Island Rattlesnake
The Aruba Island rattlesnake is found only on the island of Aruba in the Caribbean. This species is critically endangered, with an estimated 230 adults in the wild.
Adults grow to be about 35 inches long and weigh about one kilogram. They’re typically light brown or tan in color (almost pink) with darker brown diamond-shaped markings.
11. Catalina Island Rattlesnake
The Catalina Island rattlesnake is found in the Isla Santa Catalina in Mexico’s Gulf of California. This species is small in size, about 28.8″ in length, and has one distinctive feature that sets it apart: it doesn’t have a rattle.
Most snakes of this little venom species have a light cream base color and red-brown blotches with a black and white band around the tail.
These are just a handful of the many rattlesnake species, which are each unique in their own way. From venom types to appearances, rattlesnakes will surprise you in every way – just don’t get too close.
Conservation Status
Most rattlesnake species are not classified as endangered, according to the IUCN (International Union for the Conservation of Nature).
The Aruba Island rattlesnake is considered critically endangered, and there are three other species on the Red List of Threatened Species:
- Santa Catalina Island rattlesnake: Critically endangered due to its limited range. Human and feral cat killings are two of the biggest threats to this species of snake.
- The Tancitaran dusky rattlesnake: Considered endangered because It’s only found in one small area of Mexico.
- Long-tailed rattlesnake: Classified as “vulnerable.” This species is found in western Mexico and is considered very rare. Agriculture and logging are the biggest threats to this species.
Other Fun Rattlesnake Facts
1. Rattlers Have Predators
They may be venomous, but rattlesnakes do have predators. The rattlesnake’s most dangerous predator is the king snake. The rattlesnake is a delicacy to the king snake.
2. Rattlesnakes are Symbolic in Many Cultures
Rattlesnakes were a key part of Aztec mythology and were often seen in art, jewelry and architecture.
The ancient Mayans viewed the rattlesnake as a link to the “other world” and called these snakes a “vision serpent.”
In some Christian sects in the southern United States, people partake in ritual where they handle rattlesnakes. The service is inspired by Bible verse Mark 16:17-18, which says “In my name… they will pick up snakes with their hands.”
The rattlesnake was symbolic for Colonials while fighting the Revolutionary War, and is depicted on the Gadsden Flag.