Bryan McAllister’s personal reference notebook
July 27, 2026Short & citedBlog
Civic Viewpoint.
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Kept by Bryan McAllister — short guides, clear facts, and the Canadian angle when it matters.
Field Notes • Reptile

Snake

A snake is a legless reptile in the suborder Serpentes, classified within the order Squamata.

Updated July 27, 20261 min readCited sources

Snakes are legless reptiles in the suborder Serpentes, with more than 3,400 species worldwide. They live on every continent except Antarctica and range from harmless constrictors to venomous species.

What it is

Snakes are an elongated, limbless group of reptiles classified under the order Squamata. They are ectothermic (cold-blooded) and covered in scales. Species vary enormously in size, colour, and behaviour, with major lineages including constrictors, vipers, elapids, and colubrids.

Key details

Snakes move using muscular contractions and body scales in four main styles: serpentine, concertina, rectilinear, and sidewinding. They shed their outer skin regularly to grow. Diet depends on species – many eat rodents, birds, frogs, insects, or other small animals. Constrictors squeeze prey; venomous snakes use fangs to inject venom.

Why it matters

Most snake species are harmless to people, but a minority are venomous and can cause serious injury or death. Snakes generally avoid humans and bite only when threatened. In Canada, native snakes include harmless species and a few venomous rattlesnakes. They play a valuable role in ecosystems by controlling rodent populations.

In short

  • Snakes are limbless reptiles with over 3,400 species.
  • They move using serpentine, concertina, rectilinear, or sidewinding locomotion.
  • Most are non-venomous; only a minority pose a risk to humans.
  • Snakes live on every continent except Antarctica, including parts of Canada.
Canadian angle

Canada has native snake species in several regions, including harmless species and a small number of venomous rattlesnakes in some areas. Snakes are part of local ecosystems and help control rodent populations.[13]

Quick questions

How many snake species are there?
More than 3,400 snake species are recognized in current reference sources, though totals vary slightly by classification system.
Are snakes dangerous?
Most snake species are not dangerous to humans, but some are venomous and can cause serious harm. Snakebite risk depends on species, location, and whether the animal feels threatened.
What do snakes eat?
Snakes are carnivores. Depending on the species, they may eat rodents, birds, frogs, fish, insects, slugs, or other small animals.

Sources

  1. Britannica — https://www.britannica.com/animal/snake
    Supports: General definition, species count, venom prevalence, and snake locomotion types.
  2. NC State Extension Publications — https://content.ces.ncsu.edu/snakes
    Supports: Classification, ectothermy, movement, shedding, and venom delivery.
  3. Mass Audubon — https://www.massaudubon.org/nature-wildlife/reptiles-amphibians/snakes
    Supports: Habitat range, non-venomous majority, ectothermy, and general behaviour.
  4. Washington Department of Fish and Wildlife — https://www.wdfw.wa.gov/species-habitats/living/snakes
    Supports: Diet, ecological role, and typical non-aggressive behaviour.
  5. Reptile Centre — https://www.reptilecentre.com/blogs/reptile-blog/types-of-snakes
    Supports: Broad snake groupings and example UK species.
  6. Wikipedia — https://www.wikipedia.org/wiki/Snake
    Supports: Approximate species count and broad taxonomic context.