# Garter Snake (*Thamnophis sirtalis*)

> The garter snake is one of the most common and widespread snakes in North America, found in meadows, marshes, woodlands, and gardens from Canada to Mexico. It is a slender snake, typically 0.5 to 1.3 m long and about 150 g, usually striped in yellow or green along a darker body. Harmless to people, it slithers actively by day hunting worms, amphibians, and fish, and lives around four to ten years.

- **Category:** Reptile
- **Conservation status (IUCN):** Least Concern
- **Range:** Meadows, marshes, and gardens across North America, one of the most widespread snakes on the continent.
- **Canonical page:** https://globalanimalguide.org/animals/garter-snake/
- **Last reviewed:** 2026-07-16

## Scientific classification

- **Kingdom:** Animalia
- **Phylum:** Chordata
- **Class:** Reptilia
- **Order:** Squamata
- **Family:** Colubridae
- **Genus:** Thamnophis

## Facts at a glance

| Attribute | Value |
| --- | --- |
| Scientific name | Thamnophis sirtalis |
| Diet | Carnivore |
| Habitat | Meadows, marshes, woodlands, and gardens |
| Lifespan | 4–10 years in the wild |
| Length | 0.5–1.3 m (1.5–4.3 ft) |
| Weight | About 150 g (5 oz) |
| Conservation status | Least Concern (IUCN) |

## Appearance and identification

Garter snakes are best known for the long stripes that run the length of the body, usually one down the back and one along each side, in yellow, green, or cream against brown, grey, or black. Adults are slim and typically measure 0.5 to 1.3 m (about 1.5 to 4.3 ft) and weigh around 150 g. There are many regional colour forms, so patterning varies widely across the species' huge range. The keeled scales give the skin a slightly rough, matte look rather than a glossy sheen.

## Diet and hunting

The garter snake is a carnivore with a broad appetite, eating earthworms, slugs, amphibians, small fish, and the occasional rodent or nestling. It slithers actively through vegetation and shallow water by day, using sight and a flicking tongue to track prey rather than lying in wait. Some populations tolerate the toxins of newts and toads that would poison other predators. Prey is seized in the jaws and swallowed whole, as the snake has no venom potent enough to subdue large animals.

## Habitat and range

Few snakes are as adaptable, and the garter snake ranges from Canada through the United States into Mexico across an enormous variety of habitats. It thrives in damp meadows, marshes, pond edges, woodland, and suburban gardens, rarely far from water. This tolerance of cool climates lets it live farther north than almost any other North American snake. Its willingness to live alongside people makes it one of the reptiles most familiar to gardeners.

## Reproduction and hibernation

Garter snakes give birth to live young rather than laying eggs, producing litters that can number from a handful to several dozen. In colder regions they spend winter in communal dens called hibernacula, sometimes gathering by the hundreds or thousands in the same rocky shelter. When they emerge in spring, males may form writhing mating balls around a single female. The newborn snakes are fully independent from birth and receive no parental care.

## Defence and predators

When threatened, a garter snake first tries to flee, slithering quickly into cover. If cornered it may flatten its body, strike, or release a foul-smelling musk from glands near the tail to deter a predator. Its saliva contains a mild toxin that helps subdue small prey but is harmless to humans, causing at most minor irritation. Hawks, larger snakes, raccoons, and domestic cats are among its many predators.

## Lifespan and conservation

In the wild garter snakes typically live four to ten years, though predation means many do not survive their first year. The species is listed as Least Concern by the IUCN and remains abundant across its range. A few localised subspecies, such as the San Francisco garter snake, are threatened by habitat loss and are protected. For the species as a whole, adaptability and a varied diet keep populations healthy.

## Frequently asked questions

### Are garter snakes dangerous to humans?

No. Garter snakes are essentially harmless to people; they have only a very mild toxin in their saliva that helps them subdue small prey. A bite may cause minor irritation or swelling but is not medically dangerous.

### What do garter snakes eat?

They are carnivores that eat earthworms, slugs, amphibians such as frogs and toads, small fish, and occasionally rodents or nestlings. They hunt actively by day, tracking prey by sight and scent.

### How big do garter snakes get?

Most garter snakes are 0.5 to 1.3 m long (about 1.5 to 4.3 ft) and weigh around 150 g. They are slender snakes, so even the longest individuals stay lightweight.

### Do garter snakes lay eggs?

No, garter snakes give birth to live young rather than laying eggs. A single female can produce anywhere from a few to several dozen fully independent offspring in a litter.

### How long do garter snakes live?

In the wild they usually live four to ten years, although heavy predation means many die young. Individuals in captivity can live somewhat longer under stable conditions.

### Where are garter snakes found?

They range across North America from Canada to Mexico and live in meadows, marshes, woodlands, pond edges, and gardens. Their tolerance of cool climates lets them live farther north than almost any other North American snake.

## Sources

- [IUCN Red List — Thamnophis sirtalis.](https://www.iucnredlist.org/search?query=Thamnophis%20sirtalis&searchType=species)
- [Animal Diversity Web — Thamnophis sirtalis. University of Michigan Museum of Zoology.](https://animaldiversity.org/accounts/Thamnophis_sirtalis/)
- [Wikipedia — Garter Snake.](https://en.wikipedia.org/wiki/Common_garter_snake)

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Source: Global Animal Guide (https://globalanimalguide.org/animals/garter-snake/). Licensed CC BY-NC 4.0 — free for non-commercial reuse with attribution.