Rattlesnakes are venomous snakes characterized by a segmented rattle at the tip of the tail that
produces a buzzing sound when vibrated.
There are about 36 known species of rattlesnakes.
Rattlesnakes are native to the Americas, ranging from southern Canada to central Argentina but are
most abundant and diverse in the southwestern United States and northern Mexico.
Rattlesnakes can be found in a wide variety of habitats. They are most abundant in the desert sands of the Southwest, but they also like rocky areas, prairies, marshes and forests.
Rattlesnakes have a lifespan of 10 to 25 years in the wild.
Most rattlesnake species are 0.6 to 1.2 meters (2 to 4 feet) in length.
The largest rattlesnake species is the eastern diamondback rattlesnake (Crotalus adamanteus), reaching up to 2.4 meters (8 feet) in length and weight 1.8 to 4.5 kilograms (4 to 10 pounds).
The smallest rattlesnake species is the ridge-nosed rattlesnake (Crotalus willardi) measuring from 30 to 60 centimeters (1 to 2 feet) in length.
Rattlesnakes are known for their relatively heavy bodies and diamond-shaped heads.
Rattlesnake skin has a set of overlapping scales which cover the entire body, providing protection from a variety of threats including dehydration and physical trauma.
The skin of rattlesnakes is intricately patterned in a manner that camouflages them from their predators. Rattlesnakes do not generally have bright or showy colors, instead relying on subtle earth tones that resemble the surrounding environment.
Rattlesnakes get their name from special structures on the tip of their tail. Their “rattle” is made of rings of keratin (the same material our fingernails are made of). When vibrated, the rattle creates a hissing sound that warns off potential predators. It is an extremely effective and highly evolved predator-avoidance system.
Their eyes are acute during daylight conditions but also well adapted to nocturnal use. They have vertical pupils, like cat’s eyes.
Rattlesnakes are pit vipers — they have heat sensing organs located in pits near the eyes. The heat-sensitive pits detect the prey’s heat, and nerves transmit this information to the same area in
the brain that receives optic nerve impulses. It is accurate to say the rattlesnake “sees” a heat
image of its prey, and it can strike in darkness if the prey is even slightly warmer than its
Rattlesnakes have an exceptionally keen sense of smell. They can sense olfactory stimuli both through their nostrils and by flicking their tongues, which carry scent-bearing particles to the Jacobson’s
organs in the roof of their mouths.
All rattlesnakes are venomous. Some are more venomous than others: the species and habitat of the
snake determines how potent its venom is and can vary within a single species.
The rattlesnake’s fangs inject venom into its prey when it strikes at a speed of about five-tenths of a second!
Venom is delivered from glands above the upper jaw, through the venom duct and out the enlarged, hollow teeth, known as fangs. The rattlesnake can control the amount of venom it releases.
Their venom paralyzes the prey, which they then swallow whole.
Rattlesnakes only look for food when they’re hungry. An adult rattler goes about two weeks between meals, on average, depending on how large its last meal was. Younger rattlesnakes eat more often, about once a week.
Almost all reptiles, including rattlesnakes, are cold-blooded. As cold-blooded creatures, rattlers depend on the sun to warm them up to optimal temperatures and shady places to cool off.
Those in more temperate zones, where temperatures can drop to 4°C (40°F), enter a period of brumation, in the winter which is dormancy similar to hibernation. To keep from freezing, rattlesnakes congregate in dens and form swarming balls with their bodies.
Rocky crevices, burrows, and leaf litter all make safe dens for rattlesnakes.
Rattlesnakes often return to the same den, year after year, sometimes traveling several miles to get
there.Most rattlesnake species mate during the summer or fall, while some species mate only in the spring, or during both the spring and fall.
Rattlesnakes are ovoviviparous. This means they give birth to live young after developing and
retaining the eggs inside their bodies. Most of the time there are 8 to 10 babies born at once.
Young rattlers are almost independent just minutes after they are born, and in some species, their
venom is more toxic than the adults’.
Rattlesnakes generally take several years to mature, and females usually reproduce only once every
Their natural predators include birds of prey, such as owls, eagles and hawks, as well as foxes, coyotes, badgers, feral pigs and other snakes. Newborn rattlesnakes are especially susceptible to being hunted.
Most species of rattlesnakes are not endangered, according to the International Union for the Conservation of Nature (IUCN).
Rattlesnakes play a very important role in their ecosystems by controlling small mammal populations.
Rattlesnakes have an undeserved reputation for being aggressive, even though they shun human contact and attack only when directly provoked, rattling their tails as a warning before striking.
They also hiss, a second element of its warning posture that is often overlooked and overshadowed by
Most people bitten by rattlesnakes have inadvertently stepped on them — so watch where you’re walking!
Their bites can be dangerous but are very rarely fatal to humans.
Aztec paintings, Central American temples, and the great burial mounds in the Southeastern United
States are frequently adorned with depictions of rattlesnakes, often within the symbols and emblems
of the most powerful deities.
The rattlesnake became a symbolic animal for the Colonials during the Revolutionary War period, and is
depicted prominently on the Gadsden Flag. It continues to be used as a symbol by the United States
military, and political movements within the United States.