How to Identify a Venomous Snake (8 Tips)

When it comes to wildlife encounters, it’s never a good idea to get too close, however there are some animals that you really don’t want to get too close to. Venomous snakes are certainly an example of a type of wildlife that you should give plenty of space to. In this article we’re going to discuss the difference between venomous and poisonous, and how to identify a venomous snake.

Depending on what part of the world you are in, there could be a chance of encountering a venomous snake- whether that is on accident or on purpose! It’s always a good idea to be able to identify potentially dangerous wildlife, and with snakes there are a few things you can look out for to give you an idea of whether or not they are venomous.

credit: Samantha Smith

How to identify a venomous snake – 8 tips

There is no single rule, rhyme or trick that will definitively tell you whether or not a snake is venomous. The only way to be 100% sure if a snake is venomous is to be familiar with the species and their lookalikes, which requires time and practice.

That being said, the following tips should help you identify a venomous snake, should you come across one. Just know that these rules and tips have exceptions!

*Any one of the below should not be the only factor used in determining if a snake is venomous, proper snake identification is the only way to be 100% sure a snake is venomous!

1. Head Shape

Now pretty much all snakes have a triangle shaped head, however Pit Vipers (a family of venomous snakes) have exceptionally broad, triangle shaped heads. Their broad heads will be distinctly wider than the width of their neck, but these snakes are typically larger bodied snakes anyways.

The Pit Viper family includes snakes like Rattlesnakes, Water Moccasins, and Copperheads which are found in North America, however there are species of Pit Vipers found all over the world.

2. Pit organs

Pit Vipers get their name from their pit organ. The pit organs are small holes (or pits) that are located between the nostril and the eye of a Pit Viper. They can be difficult to see and don’t look much different than a nostril. That being said, if you can see a snake’s pit organ you are probably too close!

Pit organs essentially give Pit Vipers “heat vision” that allows for Pit Vipers to detect their warm-blooded prey. However, Pit Vipers are not the only snakes with pit organs, Boas and Pythons (which are both non-venomous) also have pit organs.

Gaboon Viper

4. Coloration and Patterns

For many animals, being brightly colored can be great for attracting mates. But being brightly colored also comes with the risk of being easily detected by potential predators. One strategy that has evolved in several different kinds of animals over time is aposematic coloring.

Aposematic coloring is essentially the use of bright colors and bold patterns to ward off predators. The theory behind it is that over time, predators have tried to eat these brightly colored animals and had bad experiences with them through either getting bitten or sick, or worse, dying. The predators that survived these encounters then begin to associate these bright colors and patterns with a bad experience.

credit: Samantha Smith

This strategy works so well for snakes that there are even non-venomous snakes that have piggy backed off of their venomous counterparts. Often times, non-venomous snakes have evolved to have similar colors and patterns of the venomous snakes in their region, which helps them to prevent being eaten. This is called mimicry and also serves as a good example of there being exceptions to every rule.

In North America, Coral Snakes are an example of a brightly colored and boldly patterned venomous snake. They do have a non-venomous mimic, the Scarlett King Snake which shares a very similar color scheme and pattern.

5. Pupil Shape

Many species of Pit Vipers have cat-like or slit shaped pupils as opposed to more round, spherical pupils. That being said, snakes’ pupils react to changes in light (like ours) so with less light, their pupils will get bigger and rounder. Coral Snakes, on the other hand are highly venomous and have round pupils.

credit: Samantha Smith

However, if you are close enough to see the distinct shape of a snake’s pupils then you are probably too close!

6. Behavior

Certain snakes with different dispositions or lifestyles will behave differently. Obviously, these behaviors are highly dependent on the individual and the situation. In North America, we have Rattlesnakes which are ambush style predators.

Ambush style predators are somewhat lazy snakes, they wait for the prey to come to them before ambushing them. Snakes are terribly afraid of humans and will do their best to steer clear of them. For some species, this means getting away as quickly as possible. For other species, this means sitting still and hoping to remain unseen, and if that doesn’t work then they will stand their ground.

Assuming you are in North America, if you encounter a snake and it sits still and stands its ground and doesn’t rush off, then this could mean that it is a venomous snake, more specifically, a Rattlesnake.

7. Furrowed brow

Some venomous snakes, mainly Vipers, have a protruding scale, called the supraocular scale, near their eye that gives them a furrowed brow look. This protruding scale makes these snakes look particularly angry and are a good sign that you should keep your distance.

In North America, you will see Rattlesnakes, Water Moccasins, and Cottonmouths with a “furrowed brow”. However, Coral snakes do not have these protruding scales and are very venomous.

8. Practice your Snake identification skills

As mentioned earlier, there are exceptions to every rule. There is unfortunately no single easy trick to telling a venomous snake from a nonvenomous snake. The only way is to know the venomous snakes in your area and ways to identify them. So, if you are really keen to bulk up your venomous snake knowledge then there are loads of resources to use to help practice identification skills. I highly recommend picking up a field guide local to your region to get familiar with your native venomous snakes!

If you don’t have the time or desire to work on your wildlife identification skills, then you could be in luck! You may be able to find local social media groups that are specifically dedicated to helping non-snake lovers identify snakes in their back yards. There is even an app dedicated to helping people get snakes identified.

Difference between venomous and poisonous snakes

In most cases, the snakes that people call “poisonous” are actually venomous. Venomous relates to a snake injecting its venom into its victims through the use of fangs, while poisonous means that a poison or toxin that is ingested or consumed. However, there are some species of snakes that are poisonous due to what they eat.

Conclusion

To sum things up, there is no hard and fast rule to identify a venomous snake from a non-venomous snake. These rules and tips have exceptions and are highly dependent on where you are in the world.

It is definitely a good practice to be familiar with your local wildlife, venomous or not. In areas where there are venomous snakes, it is especially important to know which animals are potentially dangerous so that you are able to give these animals extra space. But keep in mind that snakes are more afraid of humans than we are of them and would much prefer to be as far away from us as possible.

Many people want a quick way to identify a venomous snake so that they can decide whether or not they “need” to go kill the snake they’ve found in their garden. Venomous or not, there is no need to kill a snake. Snakes are great for pest control and will almost always get on their way if you leave them to it.

That being said, if you fear that there is a venomous snake where it shouldn’t be, like your house or garage, there are often people or services that you can call to come and have the snake removed for you. That way everybody remains unharmed. After all, most people that are bitten by venomous snakes are people that have no business trying to handle or remove them.

The safest way to interact with snakes is to assume that all snakes are venomous and to give them plenty of space.