Is the common garter snake venomous?

The common garter snake is harmless. Harmless. Garter snakes have a very mild toxin in their saliva that matters to earthworms and amphibians and not at all to people. Some individuals cause mild local swelling in a bite, which is not a medical concern.

How do you identify a common garter snake?

Three lengthwise stripes running head to tail. No North American pit viper is striped this way. Slender build with keeled scales and a narrow head.

Where do common garter snakes live?

They are found in 48 US states, in habitats including grassland, suburban, wetland, woods and farmland.

Common Garter Snake

Harmless

Thamnophis sirtalis · also called garden snake, gardener snake, striped snake

The garter snake is the snake most Americans meet first — in a garden, under a woodpile, or basking on a path. It is found in more of North America than any other snake, from Florida to Canada, and it is entirely harmless. Its lengthwise stripes make it one of the easiest species to recognise, because very few dangerous snakes are striped.

Venom: Harmless. Garter snakes have a very mild toxin in their saliva that matters to earthworms and amphibians and not at all to people. Some individuals cause mild local swelling in a bite, which is not a medical concern.
Adult length: 18–36 inches (46–91 cm)
Markings: Three pale lengthwise stripes — one down the spine and one along each side — on a dark ground, often with a checkerboard of dark spots between them. Colour varies enormously by region.
Habitat: grassland, suburban, wetland, woods, farmland
Family: colubrid
Range: 48 US states

How to identify a common garter snake

Three lengthwise stripes running head to tail. No North American pit viper is striped this way.
Slender build with keeled scales and a narrow head.
Round pupil, no facial pit.
Active by day, often in gardens and near water.

What it does when it sees you

Flees when approached. If grabbed it releases a memorably foul musk and may bite, which amounts to a scratch. Gives birth to live young in late summer, so small ones appear in numbers in August and September.

What the common garter snake is confused with

One test settles each of these.

Ribbon snake

Ribbon snakes are more slender with a longer tail and crisper stripes, and are more tied to water. Both are harmless.

Before anything else

Back away and leave it alone. A snake that can see you leaving has no reason to bite. Most bites in the United States happen to people who picked up, cornered, or tried to kill a snake.
Never handle a snake to identify it. Every identification on this site can be made from a photo or from several feet away.
If someone is bitten, call emergency services now. Keep the limb still and below the heart, remove rings and watches, and go to hospital. Do not cut, suck, apply ice, or use a tourniquet — all of these make outcomes worse.
Do not try to catch the snake for identification. A photo from a distance is enough, and hospitals treat symptoms rather than species.

In the US, the Poison Help line is 1-800-222-1222. This site is a reference, not medical advice.

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