Do Garter Snakes Bite? (Are they Venomous?)

Garter snakes do bite, but they cannot seriously injure humans. It is because their fangs are not effective in injecting venom.  

For many years, people thought that garter snakes are harmless. However, scientists are finding more and more evidence that they actually have some weak venom in their fangs.

Nevertheless, this venom is not fatal. While a garter snake bite should be examined and treated by professionals immediately, in general it will usually not cause much long-term harm.

Do Garter Snakes Bite

About Garter Snakes

Do they bite?Yes, Garter snakes bite when feeling threatened.
Are they venomous?Yes, garter snakes release a fluid called Duvernoy’s secretion which has some toxicity, but it is very low.
Do they have teeth and fangs?Yes, garter snakes have both teeth and fangs. They have three types of teeth: recurved, curved, and linear.

If you have been bitten by a snake, seek professional help immediately. Do not approach a snake or a snake habitat. The below is general information for entertainment purposes only.

Do Garter Snakes Bite?

Yes, garter snakes do bite if under threat. A recent study concluded that garter snakes appear to be more aggressive in hot weather.

Twenty-four common garter snakes were involved in the study. Specifically, the species they used was the Thamnophis sirtalis. In the laboratory, scientists experimented under three temperatures: 10, 20, and 30 degrees Celsius.

They used the human finger as the predatory stimuli, coaxing the snakes to do something. They found out that under low temperature, or cold temperature, the garter snakes were passive. They displayed signs of increased passiveness or the equivalent of decreased aggression.

The theory is that garter snakes seem to know that an aggressive approach is not practical during cold temperatures. As cold-blooded animals, they need to conserve their strength in cold temperatures. If they bite under low-temperature conditions, they lose energy.  

Related Article: Do Garter Snakes Eat Fish?

Are Garter Snakes Venomous?

Garter snakes do have toxicity, but it is not as toxic as the venom of many other snakes. In fact, there’s a belief that the toxic chemicals garter snakes produce may be designed for digestion rather than immobilizing prey. They cannot seriously injure humans except for rare instances of allergic reaction.

However, one must not mistake this lack of venom toxicity as an utterly harmless issue. Some people have allergies, and the allergic reaction can kill a person from a garter snake’s bite.

There was one case of a 13-year-old victim who suffered from multiple problems like edema and ecchymosis of the bitten hand. This victim has had prolonged exposure bites from the eastern garter snake.

The victim went to the hospital and received care and eventually recovered. Nevertheless, this case gave rise to the theory that toxicity among various species of the garter snake was possible, even if it was long thought that they had no venom.

Ecchymosis is bruising. It happens if blood leaks out of the blood vessel under the skin. As such, the skin may turn dark purple.

Another study concluded that the venom of a garter snake is highly toxic to mice. Their bites cause bleeding in the lungs of mice. They also damage the diaphragm and stomach lining. The mice that got more dosage showed signs of systemic hemorrhaging.  

Related Article: What Eats Garter Snakes?

Do Garter Snakes have Venom Sacs?

It appears that the toxic chemical of garter snakes is held in their Duvernoy’s gland, which produces ‘Duvernoy’s secretion’.

The Duvernoy’s gland is a light yellow in garter snakes, and its location is lateral to the mouth. The Duvernoy’s gland is not the same as the venom sac. Viperids and elapids do not have this gland.

There is a lot of speculation about Duvernoy’s gland. Many scientists believe that it is the equivalent of a venom sac. However, venom glands and Duvernoy’s gland are anatomically different. They also have different functions.

Some scientists believe that the Duvernoy’s gland is a primitive form of the venom gland. However, there is evidence proving that the Duvernoy’s gland helps in swallowing, not in poisoning prey.

Types of Garter Snake Teeth

The garter snake has three types of teeth. These are called recurved tooth, curved tooth, and linear tooth.

  • Recurved – a kind of tooth with the shape of the letter “S.” This tooth helps the snake keep its prey in its clasp after biting.
  • Curved – a kind of tooth that is curved backwards. The shape is like a crescent moon. Snakes use this tooth to pull back food towards their esophagus.
  • Linear – a straight tooth that allows the snake to penetrate deeper into the prey’s body.

A scientific study revealed that each tooth has a pair of dental ridges. The ridges are in a position where they are opposite one another, along the sides of the tooth. The ridges do not have the same length or position. Instead, they vary according to the function of the tooth they support.

The study also concludes that there are different anatomical functions for these ridges. First, the recurved teeth work great for snaring or trapping the prey. Second, the ridges also secure the teeth, giving them more cutting power in the digestion process.   

Are Garter Snake Teeth Powerful?

Garter snake teeth are not as powerful as the teeth of vipers and pythons, but they can still inflict damage to mammals. A garter snake’s teeth are short, but they are sharp.

The teeth can inject a small amount of venom and can immobilize prey.

Garter snakes also use their teeth to push prey back as they attempt to swallow. Like many snakes, they do not chew but instead, swallow their prey whole.

A garter snake’s teeth are powerful enough to catch prey such as: 

  • Mammals, birds and fish
  • Amphibians and reptiles
  • Insects and non-insect arthropods
  • Crustaceans and molluscs

Garter snakes are better off hunting prey smaller than them. Because of the size of their teeth, and the lack of a powerful venom, they cannot protect themselves from other predators. Some other snakes even consider garter snakes as part of the menu, including:

  • Milk snakes
  • Coral snakes
  • Frogs
  • Raccoons
  • Shrews
  • Foxes
  • Birds like cows and blue herons

Some fish and snapping turtles also eat garter snakes. 

Related: 12 Least Venomous Snakes in the USA


Contrary to popular belief, garter snakes have teeth. There are three types of teeth that have different functions. One tooth is for ensnaring, one for pushing food, and one for grinding and slicing. 

The venom of the garter snake is up for debate. Some claim that since it has no venom gland, it cannot possibly have venom. But it has a Duvernoy’s gland, which produces a toxic chemical. Some argue that this chemical is for digestion, not for poison.

The garter snake can still pose a danger to humans, but not as much as its highly venomous cousins. While garter snakes have teeth and produce toxic chemicals, they are still prey to bigger animals and snakes.

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