Serpentes (suborder)

Snake

Every continent except Antarctica, plus many oceanic islands, with around 4,000 species from desert to rainforest to open sea.

Group: Serpentes
IUCN: LC
Reviewed: 2026-08-20

Read this first

Popular claims checked

The claim: Snakes dislocate or unhinge their jaws to swallow large prey.

What the evidence says: Nothing dislocates. The two halves of a snake's lower jaw are not fused at the front as in mammals but joined by an elastic ligament, so they can move independently and spread apart; the quadrate bones add further mobility. The jaw is doing exactly what it evolved to do, within its normal range of motion. 'Unhinging' describes an injury, not the mechanism.

Why it persists: The visual result looks like a dislocation, and the phrase is vivid and short.

Where you'll meet it: Nature documentaries and textbooks · Almost universal in popular science writing

Sources (1)

Academic bookCundall, David, Greene, Harry W. (2000)
Feeding in snakesFeeding: Form, Function and Evolution in Tetrapod Vertebrates, Academic Presspp. 293-333

The claim: The snake universally symbolises evil, deceit and temptation.

What the evidence says: This reading is specifically Abrahamic and is not general. In the Greek cult of Asklepios live snakes were kept in healing sanctuaries and the serpent-entwined staff is still the emblem of medicine. For the Hopi, snakes are associated with water and rain and are petitioned in ceremony. Elsewhere serpents appear as creators, ancestors and guardians. Treating the Genesis reading as the snake's meaning promotes one tradition to a universal.

Why it persists: Genesis is foundational to the cultures that produced most English-language symbolism writing, which makes the association invisible as a cultural specific rather than obviously one reading among many.

Where you'll meet it: Western culture broadly, following the Genesis account · Popular symbolism guides presenting this as the snake's meaning

Sources (2)

Academic bookEdelstein, Emma J., Edelstein, Ludwig (1945)
Asclepius: A Collection and Interpretation of the TestimoniesJohns Hopkins University Presspp. 139-180
EthnographyFewkes, Jesse Walter (1897)
Tusayan Snake CeremoniesSixteenth Annual Report of the Bureau of American Ethnology, Smithsonian Institution, Bureau of American Ethnologypp. 267-284

Verified observation

In nature

A limbless squamate reptile that smells in stereo with a forked tongue, sheds its skin whole at intervals, and in several lineages detects infrared. Jaw mobility allows swallowing prey wider than the head.

sensesEstablished

The forked tongue delivers scent particles separately to each side of the vomeronasal organ, letting the snake compare concentrations between tips and read a chemical gradient directionally.

Sources (1)

Peer reviewedSchwenk, Kurt (1994)
Why snakes have forked tonguesScience, vol. 263pp. 7-12Open source

physiologyEstablished

Snakes shed the outer skin layer whole and periodically — ecdysis — typically several times a year, more often in rapidly growing young animals.

Sources (1)

Peer reviewedMaderson, Paul F. A. (1965)
Histological changes in the epidermis of snakes during the sloughing cycleJournal of Zoology, vol. 146pp. 121-137Open source

sensesEstablished

Pit vipers, pythons and boas detect infrared radiation through specialised pit organs, forming a thermal image that is integrated with vision in the brain.

Sources (1)

Peer reviewedGracheva, Elena O., Ingolia, Nicholas T., Kelly, Yvonne M., Cordero-Morales, Julio F., Hollopeter, Gunther, Chesler, Alexander T., Sánchez, Elda E., Perez, John C., Weissman, Jonathan S., Julius, David (2010)
Molecular basis of infrared detection by snakesNature, vol. 464pp. 1006-1011Open source

morphologyEstablished

Snake jaws are not 'unhinged': the two halves of the lower jaw are joined by an elastic ligament rather than a bony fusion, and quadrate bones allow wide independent movement.

Sources (1)

Academic bookCundall, David, Greene, Harry W. (2000)
Feeding in snakesFeeding: Form, Function and Evolution in Tetrapod Vertebrates, Academic Presspp. 293-333

evolutionSupported

Venom evolved once early in the advanced-snake lineage and has been repeatedly modified and in some lineages lost, rather than arising independently many times.

Sources (1)

Peer reviewedFry, Bryan G., Vidal, Nicolas, Norman, Janette A., Vonk, Freek J., Scheib, Holger, Ramjan, S. F. Ryan, Kuruppu, Sanjaya (2006)
Early evolution of the venom system in lizards and snakesNature, vol. 439pp. 584-588Open source

circulatory arrestEstablished

Constriction kills by circulatory arrest rather than suffocation: arterial pressure in constricted prey halves within about six seconds, followed by cardiac failure — far faster than asphyxiation would act.

Sources (1)

Peer reviewedBoback, Scott M., McCann, Katelyn J., Wood, Kevin A., McNeal, Patrick M., Blankenship, Emmett L., Zwemer, Charles F. (2015)
Snake constriction rapidly induces circulatory arrest in ratsJournal of Experimental Biology, vol. 218pp. 2279-2288Open source

heartbeat detectionSupported

Boas monitor the prey's heartbeat while constricting and keep squeezing for as long as it beats; snakes with no prior live-prey experience respond the same way to an artificial pulse.

Sources (1)

Peer reviewedBoback, Scott M., Hall, Allison E., McCann, Katelyn J., Hayes, Amanda W., Forrester, Jeffrey S., Zwemer, Charles F. (2012)
Snake modulates constriction in response to prey's heartbeatBiology Letters, vol. 8pp. 473-476Open source

acoustic illusionSupported

As an object approaches, a rattlesnake's rattle rate climbs smoothly to about 40 Hz then jumps abruptly to 60-100 Hz; in virtual-reality tests human listeners hearing that jump judged the snake to be closer than it was.

Sources (1)

Peer reviewedForsthofer, Michael, Schutte, Michael, Luksch, Harald, Kohl, Tobias, Wiegrebe, Lutz, Chagnaud, Boris P. (2021)
Frequency modulation of rattlesnake acoustic display affects acoustic distance perception in humansCurrent Biology, vol. 31pp. 4367-4372.e4Open source

wild parthenogenesisEstablished

Wild-caught copperheads and cottonmouths have produced litters with no paternal genetic contribution at all, in populations where males were present — parthenogenesis is not merely a captive artefact.

Sources (1)

Peer reviewedBooth, Warren, Smith, Charles F., Eskridge, Pamela H., Hoss, Shannon K., Mendelson, Joseph R., III, Schuett, Gordon W. (2012)
Facultative parthenogenesis discovered in wild vertebratesBiology Letters, vol. 8pp. 983-985Open source

Evidence to reflection

What the behavior can suggest

This section is interpretation, not evidence. It reads documented behavior as a human character trait — a comparison we are drawing, not something the animal intends.

communicative

Positive

The forked tongue samples the air on both sides at once, letting the snake compare concentrations between tips and follow a chemical gradient to its source.

The mechanism is comparison: two samples taken simultaneously, and direction inferred from the difference between them. Read as character, that is someone who orients by contrast rather than by absolute value — who works out where to go by noticing which side is stronger. The snake is not being analytical; stereo chemoreception is simply how a limbless animal tracks prey.

You navigate by comparing. Give you one data point and you have nothing; give you two and you know the direction.

restless

Mixed

Snakes shed the outer skin whole, several times a year, most frequently while growing fastest.

The honest reading is less dramatic than the popular one: shedding is maintenance, and its frequency tracks growth rather than any inner turning point. Read as character, that is someone who discards the outer layer routinely because they are still getting bigger — renewal as a by-product of growth, not as a decision to become new. Note that the animal underneath is continuous; nothing is reborn.

You leave versions of yourself behind regularly, and you do not think of it as reinvention. You just outgrew the last one.

protective

Shadow

Pit vipers, pythons and boas form a thermal image through pit organs, integrated with vision in the brain, allowing them to locate warm prey in complete darkness.

An animal that senses body heat and can swallow prey wider than its own head is well equipped and largely unbothered — most snake defensive behaviour is avoidance, and striking is a last resort. Read as character, that is capability held in reserve: someone dangerous who would rather not be, and whose warnings come well before any action. The polarity is shadow because that reserve is easily mistaken for threat, which is why snakes are killed on sight far more often than they bite.

You warn before you act, and people read the warning as the attack.

Named tradition

Traditional symbolism

These accounts are attributed to specific peoples and sources. They are not merged into a generic Native tradition.

Ancient Greek healing cult of Asklepios (Asklēpiós)

5th century BCE to the 4th century CE; a historical cult, not a continuing practice. Historically documented.

Name in language: Ophis; the Asklepian staff

Live snakes were kept in the healing sanctuaries and were part of the incubation cure, in which the sick slept in the temple and were visited in dream. The snake signified renewal through shedding and the boundary between death and recovery, and the staff entwined by a single serpent remains the emblem of medicine.

Context: Attested at Epidaurus and other Asklepieia, with surviving votive inscriptions recording cures. Note the common confusion with the caduceus of Hermes, which has two snakes and wings and is a herald's staff, not a medical emblem.

Sources (1)

Academic bookEdelstein, Emma J., Edelstein, Ludwig (1945)
Asclepius: A Collection and Interpretation of the TestimoniesJohns Hopkins University Presspp. 139-180

Hopi (Hopisinom)

Documented from the late 19th century; the public Snake Dance was closed to outsiders in the 20th century. Living tradition.

Name in language: Tsu'tiva (Snake ceremony)

Snakes are associated with water and with the underworld from which rain comes, and the Snake ceremony petitions for rain in an agricultural society dependent on it. The snake is an intermediary with the powers that bring water, not a symbol of danger or temptation.

Context: Part of the Hopi ceremonial calendar. The ceremony was heavily photographed and written about by outsiders around 1900 and was subsequently closed; the Hopi Tribe has formally objected to publication of ceremonial material.

Sources (1)

EthnographyFewkes, Jesse Walter (1897)
Tusayan Snake CeremoniesSixteenth Annual Report of the Bureau of American Ethnology, Smithsonian Institution, Bureau of American Ethnologypp. 267-284

Modern Western material

Modern readings

Modern Western material, published in the 20th or 21st century. Listed to show what the popular genre claims — not as evidence about any people.

Animal-Speak (Ted Andrews)

First published 1993

Eclectic neoshamanic

Snake is presented as the totem of transformation and rebirth, tied explicitly to skin-shedding, and of kundalini life force rising through the body.

Our assessment: Modern Western synthesis. The renewal-through-shedding association is genuinely ancient and independently attested — the Asklepian cult is one documented example — but the specific package Andrews assembles blends Greek, Hindu and New Age material without distinguishing them.

Sources (1)

Modern deckAndrews, Ted (1993)
Animal-Speak: The Spiritual & Magical Powers of Creatures Great and SmallLlewellyn Publicationspp. 345-349

Core shamanism (Michael Harner, Foundation for Shamanic Studies)

First published 1980

Contemporary practice

In core shamanism the snake is a power animal of transformation and healing, retrieved on the journey; the practitioner is often taught to associate it with shedding what is no longer needed.

Our assessment: The shedding-as-renewal image is ancient and independently attested — the Asklepian healing cult is one documented case. But Harner's framework also absorbs kundalini material from a living Hindu and tantric context without attribution, and the biology does not support the transformation reading: shedding tracks growth, and the animal underneath is continuous.

Sources (3)

Modern deckHarner, Michael (1980)
The Way of the Shaman: A Guide to Power and HealingHarper & Rowpp. 57-72
Academic bookWallis, Robert J. (2003)
Shamans/Neo-Shamans: Ecstasy, Alternative Archaeologies and Contemporary PagansRoutledgepp. 29-49
Academic bookZnamenski, Andrei A. (2007)
The Beauty of the Primitive: Shamanism and the Western ImaginationOxford University Presspp. 233-264

Open research questions

Replace or supplement the Fewkes citation, given the Hopi Tribe's stated objection to publication of ceremonial material.
Add the Rainbow Serpent of Aboriginal Australian traditions with a specific named language group, or an Indian nāga tradition — both are well documented and would broaden the entry beyond two traditions.