Types of Snakes
There are nearly 4,000 species of snakes on Earth, but you don't need to memorize them to understand snakes. Almost every snake fits into a few clear groups, and the single question most people really want answered — is it dangerous? — comes down to just a handful of families. Here's how snakes are categorized, what separates a harmless garden snake from a venomous one, and a guide to the common snakes you're actually likely to encounter.
The Two Ways Snakes Are Categorized
People sort snakes in two different ways, and it helps to keep them separate:
- By danger to humans — venomous vs. non-venomous. This is the practical division most people care about, and the good news is that the vast majority of snakes fall on the harmless side.
- By family (scientific grouping) — colubrids, vipers, elapids, boas, and pythons. This is how biologists organize snakes by shared traits and ancestry, and it maps loosely onto how a snake hunts: with venom, by constriction, or by simply grabbing and swallowing prey.
Understanding both lets you make sense of any snake you meet. We'll take them in the order that's most useful: danger first, then families, then the specific snakes you're most likely to actually run into.
Most Snakes Are Non-Venomous
Of the nearly 4,000 snake species worldwide, only a minority are venomous, and only a fraction of those are dangerous to humans. The snakes you'll typically find in a yard or garden — garter snakes, water snakes, racers, rat snakes, brown snakes, and their relatives — are non-venomous and harmless. They control pests and pose no threat.
Venomous snakes do exist, and they deserve respect and distance — but they're far less common in everyday encounters than fear suggests, and each region has only a few species. The safe rule for any snake you can't identify is always the same: don't handle it, give it space, and let it move on.
The Main Snake Families
Four families cover nearly every snake you're likely to hear about or encounter. Here's what separates them.
| Family | How They Kill Prey | Venomous? | Familiar Examples |
|---|---|---|---|
| Colubrids (Colubridae) | Grab & swallow, or lightly constrict | Mostly non-venomous | Garter, rat, king, racer, water, corn, gopher, hognose |
| Vipers (Viperidae) | Venomous bite (hinged fangs) | Yes — venomous | Rattlesnakes, copperheads, cottonmouths |
| Elapids (Elapidae) | Venomous bite (fixed front fangs) | Yes — venomous | Cobras, mambas, sea snakes, coral snakes |
| Boas & Pythons | Constriction (squeezing) | Non-venomous | Boa constrictor, ball python, anaconda |
Colubrids are the family that matters most for everyday life. It's by far the largest — roughly 2,000 species — and it includes almost every harmless snake you'll ever find in a North American backyard. If you see a snake in your garden, the odds are overwhelming that it's a colubrid, and that it's harmless. The other three families are where the "famous" snakes live: the venomous vipers and elapids, and the giant constrictors.
Constrictors: Boas & Pythons
Constrictors don't use venom at all. Instead, they seize prey and coil around it, tightening with each breath the animal exhales until blood flow stops. Boas and pythons are the classic constrictors — some of the largest snakes on Earth, including the reticulated python (the world's longest) and the green anaconda (the heaviest).
A key difference between the two: pythons lay eggs (and live in Africa, Asia, and Australia), while boas give birth to live young (and live mainly in the Americas). Most constrictors aren't native to the United States — but there's a notable exception worth knowing: invasive Burmese pythons, released or escaped from the pet trade, have established a breeding population in the Florida Everglades, where they've become a serious threat to native wildlife. It's one of the country's most damaging invasive-species problems.
Venomous Snake Types
Venomous snakes fall into two main families, and in the United States they come down to just a few groups.
Vipers (pit vipers) are North America's main venomous snakes. They have triangular heads, hinged fangs that fold back when not in use, and a heat-sensing "pit" between the eye and nostril. The U.S. pit vipers are:
- Rattlesnakes — many species, widespread across much of the country
- Copperheads — eastern and central states
- Cottonmouths (water moccasins) — southeastern and south-central states
Elapids have fixed front fangs and include the world's cobras and mambas. North America has just one native elapid: the coral snake, found in the Deep South and parts of the Southwest, known for its red-yellow-black banding.
The important, reassuring point: most regions have only one or two venomous species, and many northern areas have very few or none. Learn which — if any — live where you are, and you've answered most of the "is it dangerous" question before you ever see a snake.
Common Snakes You're Likely to Encounter
Global taxonomy is interesting, but here's what most people actually want: the harmless snakes you'll genuinely run into in a North American yard, field, or pond — the ones we cover in depth with our own photos and firsthand observation.
The most common backyard snake across much of the continent — small, striped, harmless, and live-bearing. Full garter snake guide →
The harmless water snake constantly mistaken for a cottonmouth. Heavy-bodied and tied to ponds and streams. Full water snake guide →
A fast, slender, non-venomous colubrid — and the truth behind the myth that racers chase people. Full blue racer guide →
Found a tiny snake? Almost all are harmless. How to identify them and tell if one's venomous. Full baby snakes guide →
Other harmless snakes you may meet include rat snakes, king snakes (famous for eating other snakes, including venomous ones), gopher and bull snakes, brown snakes, ring-necked snakes, and hognose snakes — the drama queen of the group, which plays dead when threatened. Nearly all are beneficial colubrids doing quiet pest control.
How to Tell a Snake's Type Without Getting Close
Popular ID shortcuts — "triangular head means venomous," "check the pupils" — are unreliable and often wrong (many harmless snakes flatten their heads to look dangerous, and you should never get close enough to study a wild snake's eyes). The genuinely reliable approach is knowledge plus distance: learn the few venomous species that live in your specific region through your state wildlife agency, and treat any snake you can't confidently identify as one to leave alone. You never need to handle or approach a snake to coexist with it — and most bites happen when people try to catch or kill one.
Why Snakes Matter
Whatever their type, snakes are essential to healthy ecosystems. As predators, they control rodents, insects, slugs, and other pests — a single yard's worth of harmless snakes quietly removes pests that would otherwise need traps or chemicals. As prey, they feed hawks, owls, herons, foxes, and countless other animals. Some, like king snakes, even keep venomous-snake populations in check by eating them.
Killing snakes out of fear removes all of that benefit and is usually both unnecessary and, for many native species, illegal. Learning to recognize the harmless majority — and to give the few venomous species their space — is the foundation of coexisting with one of nature's most misunderstood animals. Snakes are just one part of the bigger picture we cover across all our wildlife guides.
The Snakes We Actually Live With
Every snake guide on this site comes from real observation — the garter snakes, racers, and water snakes that share our habitat, photographed and watched firsthand rather than pulled from a stock library. You learn a lot more about a snake by living alongside it than by reading a species list.
That's the difference between a taxonomy chart and a working knowledge of the snakes in your world. Get to know the harmless majority, respect the venomous few, and snakes stop being something to fear and become something to understand.
Frequently Asked Questions
- What are the main types of snakes?
- Snakes are grouped into a few main families: colubrids (the largest family, mostly harmless — garter, rat, king, and racer snakes), vipers (venomous — rattlesnakes, copperheads, cottonmouths), elapids (venomous — cobras, mambas, coral snakes), and boas and pythons (non-venomous constrictors). Most snakes people encounter are harmless colubrids.
- How many types of snakes are there?
- There are nearly 4,000 snake species worldwide, spread across about 30 families. The great majority are non-venomous, and only a small fraction are dangerous to humans.
- What is the difference between venomous and non-venomous snakes?
- Venomous snakes inject venom through fangs to subdue prey and can be dangerous to humans; non-venomous snakes kill by grabbing and swallowing prey or by constriction. Most snakes are non-venomous, and each region has only a few venomous species.
- What family are most backyard snakes in?
- Most harmless backyard snakes are colubrids (family Colubridae), the largest snake family with roughly 2,000 species. Garter snakes, rat snakes, king snakes, racers, and water snakes are all colubrids.
- What are constrictor snakes?
- Constrictors are non-venomous snakes — mainly boas and pythons — that kill by coiling around prey and squeezing until blood flow stops. Pythons lay eggs and live in Africa, Asia, and Australia; boas give birth to live young and live mainly in the Americas.
- What venomous snakes live in the United States?
- U.S. venomous snakes are mainly pit vipers — rattlesnakes, copperheads, and cottonmouths — plus one elapid, the coral snake. Most regions have only one or two of these, and some northern areas have very few or none.
- How can I tell what type of snake I found?
- The most reliable way is to learn the few venomous species in your specific region through your state wildlife agency, and to identify harmless species by their features. Avoid unreliable shortcuts like head or pupil shape, and never handle a snake you can't confidently identify.