California Red-Sided Garter Snake: Facts, Care, and Are They Poisonous?

The California red-sided garter snake isn’t just a stunning reptile — it’s also a favorite among pet owners and herpetologists. With its vibrant colors and slender build, this snake easily earns a spot among the best pet snakes.

Thinking about caring for one? Curious if they’re venomous? Let’s dive into everything you need to know about the fascinating California red-sided garter snake.


What Is a California Red-Sided Garter Snake?

The California red-sided garter snake (Thamnophis sirtalis infernalis) belongs to the family Colubridae, a widespread group of non-venomous snakes native to North America. It’s a subspecies of the common garter snake, easily recognized by its striking black and red background, decorated with blue or yellow stripes.


What Do They Look Like?

These mesmerizing snakes are a feast for the eyes. Adult California red-sided garter snakes typically grow up to 3 feet in length but remain slender and quick-moving.

  • Base Color: Red with black speckling
  • Stripes: Longitudinal blue or yellow lines, depending on the region
  • Pattern: Interlocking red and black spots and blotches

Their vibrant, writhing patterns can sometimes cause confusion with the closely related San Francisco garter snake. Coloration varies, too — some snakes show more black, while others display vivid yellow stripes instead of blue.


Are California Red-Sided Garter Snakes Poisonous?

Technically, they produce mild toxins that help subdue their prey — like frogs, fish, and small rodents. However, their venom is harmless to humans.
If bitten, you might experience slight itching or irritation, but nothing serious. Clean the wound and bandage it; medical attention is rarely necessary unless signs of infection appear.


Are They Dangerous?

Not at all!
California red-sided garter snakes are mild-mannered, non-aggressive, and pose no real threat to humans. Their small size and low venom potency make them one of the safest snakes to encounter — or keep as pets.
If startled or stepped on, they may bite defensively, but generally, these snakes prefer to flee rather than fight.


Where Are They Found?

As their name suggests, California red-sided garter snakes are native to California’s coastal dunes, marshes, and wetlands.

  • Northern Population: Humboldt and Monterey Counties
  • Southern Population: Between Santa Barbara and San Diego Counties

Their distribution is disjunct — meaning separated — due to competition from other garter snake subspecies.


Habitat Preferences

California red-sided garter snakes are drawn to wet habitats:

  • Coastal marshes
  • Sag ponds (especially around the San Andreas Fault)
  • Lakes and shallow wetlands

They may also venture inland into grasslands and woodlands but typically stay close to fresh water for both hunting and safety.


Are California Red-Sided Garter Snakes Good Pets?

Yes! They are low-maintenance, friendly, and small, making them ideal for beginner snake owners.

  • Tank Size: Minimum 20 gallons (larger is better)
  • Substrate: Cypress mulch (retains humidity and supports healthy shedding)
  • Water Dish: Provide a large dish for both drinking and soaking
  • Temperature: They require an external heat source, like a heat lamp, for thermoregulation.

What Do They Eat?

In the wild, these snakes enjoy a varied diet of:

  • Earthworms
  • Leeches
  • Small fish
  • Frogs and their eggs
  • Small mammals and reptiles

In captivity, you can feed them:

  • Frozen-thawed rodents
  • Nightcrawlers
  • Occasional feeder fish (not exclusively, due to nutritional concerns)

Important:
They do not eat insects like crickets or mealworms.


How Long Do They Live?

With proper care, California red-sided garter snakes can live around 10 years in captivity — and sometimes even up to 17 years.


Unique Feature: Keeled Scales

One distinctive trait of these snakes is their keeled scales — scales with a raised ridge down the center.
This slightly rough texture reduces shininess, helping them blend into their surroundings and evade predators more easily.


Conclusion: Should You Get One?

Our verdict: Absolutely!
The California red-sided garter snake is a fantastic pet — small, manageable, and beautiful. They’re relatively easy to care for and perfect for anyone wanting to step into the world of reptile keeping.

If you know someone who loves snakes, or if you’re interested in learning about other fascinating reptiles, be sure to explore our other guides on rosy boas, ball pythons, kingsnakes, and more.

Happy snake-keeping!

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