50 Fun Facts About Rattlesnake

Rattlesnakes belong to which subfamily of the viper family?

The 'pit' is the heat-sensing organ between eye and nostril that lets them target warm-blooded prey in the dark.

Rattlesnakes are native to which part of the world?

Their range runs from southern Canada to central Argentina, with most species in the American Southwest and Mexico.

About how many rattlesnake species had been described as of 2024?

Between them they have 65 to 70 subspecies; the ancestral homeland is thought to be Mexico's Sierra Madre Occidental.

Which is the largest rattlesnake species?

One shot in 1946 measured 2.4 metres and weighed 15.4 kg; a $200 reward for an eight-footer, dead or alive, was never claimed.

The genus name Crotalus comes from the Greek for what?

The other rattlesnake genus, Sistrurus, means 'tail rattler' and shares a root with the Egyptian sistrum.

Which US state has the most types of rattlesnake, with 13?

Only four species are found east of the Mississippi, and just two live in South America.

Rattlesnakes prefer temperatures between 80 and 90 °F but can briefly survive lows of about what?

They can also last several days at 37 °F, which is how they cope with brumation dens through winter.

Rattlesnakes swallow their prey which way round?

That folds wings and limbs at the joints so the meal goes down at its narrowest; the snake finds the head by the odours from the mouth.

In deserts, rattlesnakes have been seen coiling and flattening their bodies to do what?

Some even bunch together in a carpet-like formation to make a bigger rain-catching platform.

Which snake is immune to rattlesnake venom and eats rattlesnakes as part of its normal diet?

A rattlesnake that smells one keeps its head low and 'body bridges', raising a coil of its back to strike and shield its head.

A rattlesnake's heat-sensing pits can detect temperature changes as small as what?

The pit works like a pinhole camera; the brain overlays its blurry thermal picture on the image from the eyes.

The effective range of a rattlesnake's heat pits is roughly how far?

Short, but enough to strike a warm mouse in total darkness.

Which nerve carries the infrared signals from a rattlesnake's pits to its brain?

The temperature sensitivity itself is linked to an ion channel called TRPA1 packed into the pit membrane.

Rattlesnake eyes lack which structure, making sharply defined images impossible?

So they rely mainly on detecting movement, though they have cone cells and some colour vision.

How often do adult rattlesnakes shed their fangs?

At least three spare pairs wait behind the working pair, and hatchlings are born with fangs and venom ready to go.

Where do a rattlesnake's fangs sit when not in use?

Muscles beside the venom glands squeeze venom through ducts into the fangs when the snake bites.

Rattlesnake venom is mainly what type?

It destroys tissue and wrecks blood clotting; the tiger and some Mojave rattlesnakes add a paralysing neurotoxin on top.

Which small rattlesnake has venom considered among the most toxic of any snake in the Western Hemisphere?

Its yield per bite is low, but drop for drop it rivals the Mojave rattlesnake's 'type A' venom.

The rattle is made of hollow interlocking segments of what material?

They are modified tail-tip scales; being hollow is what makes the buzz so loud.

The 'shaker' muscles that vibrate the rattle fire about how many times per second?

They are among the fastest muscles known and can keep going for up to three hours.

Can you tell a rattlesnake's age by counting the pieces of its rattle?

A segment is added at every shed, which can happen several times a year, and the tips snap off regularly anyway.

A newborn rattlesnake's rattle cannot make any sound until when?

It starts life with a 'prebutton', swaps that for the 'button' at its first shed, and needs two segments to click together.

A 2016 study proposed the rattle evolved from what pre-existing behaviour?

The closer a snake is related to rattlesnakes, the more its own tail-shaking resembles theirs in speed and duration.

Male rattlesnakes have thicker, longer tails than the other sex because they contain what?

A male's tail also tapers gradually rather than narrowing abruptly at the vent.

How many chambers does a rattlesnake's heart have?

Two atria and one ventricle, the standard layout for squamates; crocodiles are the reptiles with four.

Rattlesnakes reproduce how?

That is ovoviviparity; a mother can also store sperm for months and delay fertilisation until spring.

Male rattlesnakes competing over mates perform intertwined wrestling bouts known as what?

Heads and necks held vertical, the two twist together until the bigger male drives the smaller one off.

How often does a mother rattlesnake usually reproduce?

Species with long winter brumation breed least often; Mexico's lance-headed rattlesnake manages every year.

Which rattlesnake has been seen co-operatively parenting its young, behaviour reminiscent of mammals?

Mothers stay with their broods in nests for weeks and have been observed sharing the job.

Winter gatherings of rattlesnakes in underground dens can number how many?

They share the hibernacula with turtles, small mammals and other snakes, and return to the same den year after year.

For up to how long after being severed can a rattlesnake head still deliver a venomous bite?

The head can still sense, flick its tongue and strike reflexively, so 'dead' rattlesnakes deserve caution.

What proportion of US rattlesnake bite victims are male?

About half of bites happen after the victim has already seen the snake and chosen not to move away.

Roughly how many people are bitten by venomous snakes in the US each year, and how many die?

Given antivenom within two hours, the chance of recovery is better than 99%.

What proportion of rattlesnake bites result in no envenomation at all?

The snake controls how much venom it injects; a satiated snake merely surprised may give a 'dry' bite.

Milked rattlesnake venom is injected into which animals to produce antivenom?

Their antibodies are harvested from the blood, purified and freeze-dried; patients often react to the animal proteins with serum sickness.

Rattlesnake envenomations account for what share of deadly snakebite incidents among US domestic animals?

Dogs are usually bitten on the front legs and head, horses on the muzzle; more than 15,000 domestic animals are bitten a year.

The Feathered Serpent of Mesoamerican religion combined a rattlesnake with which bird?

The Maya also saw the rattlesnake as a 'vision serpent' linking this world to the next.

In 1805 Meriwether Lewis recorded a rattlesnake's rattle being fed, in water, to whom, to speed a birth?

Two rings of rattle were crumbled into water; the baby, Jean Baptiste Charbonneau, arrived within ten minutes, though Lewis doubted the medicine.

Journalist Alistair Cooke said rattlesnake meat tastes 'just like chicken, only' what?

Others have compared it to veal, frog, quail, canned tuna and, when breaded and fried, 'a sinewy, half-starved tilapia'.

The coiled rattlesnake on the Gadsden flag sits above which words?

Christopher Gadsden designed it in 1775; Benjamin Franklin had used a snake for his Join, or Die woodcut back in 1754.

Which species is depicted coiled and ready to strike on the Gadsden flag?

It was unfurled on the mainmast of USS Alfred on 20 December 1775 and became Commodore Esek Hopkins's personal flag.

Which species is likely responsible for the greatest number of snakebites in the US?

It also goes by 'coon tail', 'buzz tail' and 'Texas rattler', and probably causes most snakebite deaths in northern Mexico.

Crotalus horridus, the rattlesnake of the populous US Northeast, was first described in 1758 by whom?

The species is better known as the timber or canebrake rattlesnake and is one of the most northerly venomous snakes in North America.

The sidewinder's 'horns' are raised scales located where?

They fold down under pressure and probably protect the eyes as it pushes through rodent burrows or lies buried in sand.

The sidewinder is unique among US rattlesnakes in that which sex is larger?

Adults measure only 43 to 80 cm, small enough to leave the famous J-shaped tracks across desert dunes.

The largest rattlesnake round-up in the United States is held in which Texas town?

Held every mid-March since 1958, it draws around 30,000 visitors; many other round-ups have become no-kill educational festivals.

Sistrurus rattlesnakes (massasaugas and pygmy rattlers) differ from Crotalus in having how many head plates?

Crotalus heads are covered in many small scales; Sistrurus rattles are also smaller and give a higher-pitched buzz.

What is the winter dormancy that rattlesnakes enter, similar to hibernation, called?

They often share their winter burrows with turtles, small mammals and other snakes.

Scent particles from a rattlesnake's flicking tongue are carried to which structure in its mouth?

Males also follow the pheromone trail of a receptive female this way, sometimes trailing her for days.

Besides the tiger rattlesnake, which US species can carry a paralysing type A neurotoxin?

Most North American rattlesnakes are not neurotoxic; this presynaptic component makes these two exceptions especially dangerous.