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Wildlife Guide · Worldwide except Antarctica, Iceland, Ireland and New Zealand

Snake

Suborder Serpentes — ~3,900 species across most continents except Antarctica

Legless reptiles of land and water — diverse, often misunderstood and ecologically vital.

Varies by species (Least Concern to Critically Endangered)
A non-venomous snake with smooth scales coiled on forest leaf litter, tongue flicking to sample scent.

Image: Source: Wikimedia Commons — verify license before production

In brief

Snakes are legless reptiles (suborder Serpentes) with about 3,900 species worldwide — mostly harmless, ecologically important predators whose conservation status varies; this hub is distinct from species guides like the grass snake.

By the WARN Research & Conservation TeamChecked against IUCN Red List & CITES sourcesLast updated

Snakes are legless reptiles of the suborder Serpentes, with roughly 3,900 species on every continent except Antarctica. They range from threadsnakes smaller than a pencil to reticulated pythons exceeding six metres. Most are harmless to humans; a minority possess venom used primarily to subdue prey. Snakes control rodent and amphibian populations, serve as prey for raptors and mammals, and occupy roles from desert burrower to rainforest canopy dweller. This page is a general snake hub — distinct from species-specific guides such as the grass snake.

3,900+

Recognised snake species

~600

Venomous species (most medically significant ~200)

20%

Rough share of snake species threatened

CITES

Many species regulated in international trade

Figures sourced from IUCN Red List — reptile assessments, Smithsonian National Zoo — reptiles, Encyclopaedia Britannica — snake and other references on this page.

Snake: Quick Facts

Vital statistics and key facts about the Snake
Species count ~3,900 worldwide
Venomous ~600 species; ~200 medically significant
Limbs Absent (vestigial spurs in some boas/pythons)
Diet Carnivorous — prey swallowed whole
Distinct guide Grass snake (European species)
Main threats Habitat loss, roads, persecution

Scientific Classification

Scientific classification of the Snake
Kingdom Animalia
Phylum Chordata
Class Reptilia
Order Squamata
Suborder Serpentes

Conservation Status

IUCN Status
No single IUCN category applies. An estimated 20 percent of snake species are threatened; many lack formal assessment.
Population
Varies by species — from abundant to fewer than 100 individuals
Trend
Decreasing for many forest and wetland species
Assessed
Varies (IUCN Red List ongoing)
CITES
Many species on CITES Appendix I or II, especially pythons and rare colubrids

Snakes receive less conservation funding than charismatic mammals despite high extinction risk in some groups.

Key Facts: Snake

  • Most snakes are non-venomous and avoid humans; only a fraction of species pose serious bite risk.
  • This hub covers snakes generally — see WARN's grass snake guide for that European species.
  • Snakes shed skin in one piece, expand jaws to swallow prey whole and smell with their tongues.
  • Habitat loss, road mortality and persecution are major threats globally.
  • Snakes are not suitable pets for most owners — many species have precise temperature and dietary needs.
  • Fear-driven killing removes beneficial rodent controllers from farms and ecosystems.

What is a snake — and how does it differ from other reptiles?

Snakes evolved from legged lizard ancestors, retaining some with tiny vestigial hind limbs in boas and pythons. The elongated body, lack of eyelids and external ears, and single row of ventral scales define serpentine locomotion — lateral undulation, rectilinear crawling in tight spaces and sidewinding on sand. All snakes are carnivorous, swallowing prey whole thanks to loosely articulated jaws and stretchable skin. They detect vibrations through jaw bones, heat pits in pit vipers and boas, and chemical cues via forked tongues delivering scent to the vomeronasal organ. This guide is a hub for snakes as a group. WARN publishes separate pages for particular species — for example the grass snake of Europe — when regional search demand warrants dedicated coverage.


Venom, constriction and feeding

Venom evolved primarily for prey capture, not defence. Elapids — cobras, mambas, coral snakes — deliver neurotoxins; viperids — rattlesnakes, adders — often use haemotoxins. Colubrids include both harmless species and rear-fanged snakes with mild venom. Constrictors — pythons, boas, some colubrids — coil around prey, stopping blood flow rather than crushing bones. Prey size relative to snake girth determines diet: mice, eggs, fish, frogs or deer depending on species. Feeding frequency varies from weekly for small active snakes to monthly for large constrictors. Digestion demands warm temperatures; snakes bask to raise metabolic rate after meals.


Threats and conservation

The IUCN assesses roughly one in five snake species as threatened — often overlooked compared with mammals and birds. Deforestation, wetland drainage, roadkill and deliberate killing during snakebite panic reduce populations silently. Trade affects pythons for skins, rattlesnakes for rattles and exotic pets, and rare species for collectors. CITES lists numerous snakes on Appendix I or II. Snakebite envenoming kills tens of thousands yearly, mostly in tropical Asia and Africa. Fear drives persecution, yet medically important species deserve habitat protection alongside improved antivenom access — not indiscriminate extermination.


Snakes and people

Snakes feature in mythology worldwide — symbols of renewal, danger or medicine. Ecologically they reduce crop damage by controlling rodents; removing snakes often increases pest outbreaks. Responsible coexistence means learning local species, keeping yards clear of debris that attracts rodents, wearing boots in snake habitat and never killing non-venomous snakes out of fear. Relocation by trained handlers beats blunt instruments. WARN readers in Pakistan, Brazil and Colombia inhabit snake-rich regions where education reduces both bite risk and unnecessary killing. Wild snakes belong in functioning ecosystems, not sealed sacks in the pet trade.


Explore snake species on WARN

This page is the snake hub — for the suborder as a whole. WARN also publishes species-level guides for python, cobra, rattlesnake and anaconda, plus a dedicated European grass snake page and a twelve-species snake library linked from this guide. The species library covers ball pythons, king cobras, corn snakes, boas, green tree pythons, Burmese pythons and more — each with venom status, range, ecology and conservation notes. Use it to distinguish harmless colubrids from medically important vipers and elapids. Remember: most snakes you encounter are beneficial. Protect wetland and forest habitat in WARN partner countries and support antivenom access rather than eradication campaigns.

What WARN Does

WARN publishes free reptile education for readers in its partner-network countries — countries with rich snake faunas where misunderstanding drives persecution. This hub complements species-specific guides such as the grass snake page.

If this guide helps you understand wildlife and the pressures it faces, a gift to WARN supports habitat protection and free public education in our partner countries.

Snake: Frequently Asked Questions

How many snake species are there?

Roughly 3,900 recognised species worldwide, on every continent except Antarctica. New species are described regularly, especially in the tropics.

Are most snakes venomous?

No. About 600 species are venomous; only roughly 200 cause significant medical harm to humans. Most snakes flee or hide when encountered.

Is this page about grass snakes?

No. This is a general snake hub. WARN's grass snake guide covers that European species separately.

What do snakes eat?

Other animals — rodents, birds, eggs, amphibians, fish, invertebrates — depending on species. All snakes are carnivorous and swallow prey whole.

Why are snakes important?

They control pest populations, serve as prey for other wildlife and indicate healthy ecosystems. Removing snakes often increases rodent damage and disease risk.

Where do snakes live?

Snakes live in Worldwide except Antarctica, Iceland, Ireland and New Zealand. Snakes are legless reptiles (suborder Serpentes) with about 3,900 species worldwide — mostly harmless, ecologically important predators whose conservation status varies; this hub is distinct from species guides like the grass snake.

Are snakes dangerous?

Most are harmless to humans; a minority possess venom used primarily to subdue prey. Give wild snakes space; do not corner or handle them.

How long do snakes live?

A precise wild lifespan for snakes is not firmly established in the sources cited on this guide. Snakes are legless reptiles (suborder Serpentes) with about 3,900 species worldwide — mostly harmless, ecologically important predators whose conservation status varies; this hub is distinct from species guides like the grass snake. Where longevity figures appear in the literature they vary by region, sex and whether animals are wild or captive.

How big is a snake?

Snakes span an extraordinary range. The Barbados threadsnake reaches about 10 cm and is as thin as a spaghetti strand, while the reticulated python is the longest at over 6 m, and the green anaconda the heaviest at up to around 200 kg.

Sources & References

Population figures, conservation status and biological facts on this page are drawn from authoritative scientific and intergovernmental sources.

Terms used on this page

Plain-English definitions, from our wildlife and conservation glossary.

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