Facts About Rattlesnakes

Rattlesnakes are found only in the Americas, ranging from southern Canada down through the United States, Mexico, and Central America into Argentina.

Scientists recognize roughly three dozen rattlesnake species, with the exact count (commonly cited as 32 to 36) varying by taxonomic classification.

The eastern diamondback is the largest rattlesnake species; most adults reach 3 to 6 feet, though the record specimen measured about 7 feet 9 inches.

The pygmy rattlesnake is one of the smallest rattlesnake species, typically growing to only 18 to 24 inches long.

A rattlesnake's rattle is made of interlocking segments of keratin, the same protein found in human hair and fingernails.

A new rattle segment is added each time the snake sheds its skin, which can happen multiple times a year, so rattle length isn't a reliable way to tell a snake's exact age.

Rattlesnakes don't always rattle before striking; some strike with little or no warning, especially if startled.

Rattlesnake venom is a complex mixture of proteins and enzymes that can cause intense pain, swelling, and tissue damage at the bite site.

In some species, venom can also affect the nervous system, potentially causing symptoms ranging from weakness to breathing difficulty in severe, untreated cases.

Rattlesnakes are important predators that help control rodent populations in their ecosystems.

Rattlesnakes are preyed upon by hawks, eagles, roadrunners, king snakes, and other predators.

Rattlesnakes have heat-sensing pits between their eyes and nostrils that let them detect the infrared heat of warm-blooded prey, even in total darkness.

While generally solitary, rattlesnakes often gather by the dozens or hundreds at shared den sites to hibernate through the winter.

Female rattlesnakes give birth to live young rather than laying eggs.

Litter sizes vary by species, with most rattlesnakes giving birth to somewhere between 5 and 20 young at a time.

Rattlesnakes can go for weeks or even months between meals, since their metabolism is well suited to conserving energy between hunts.

Rattlesnakes are generally not aggressive; most bites occur when a snake is startled, stepped on, or handled rather than from unprovoked attacks.

If you encounter a rattlesnake in the wild, the safest response is to give it plenty of space and back away slowly rather than trying to move or kill it.

Rattlesnakes hold cultural significance in many Native American traditions, where they are often associated with strength, transformation, or protection.

Modern medical research has studied compounds in pit viper venom, including from rattlesnakes, in the development of treatments such as anticoagulant and diagnostic drugs.