Despite the inherent fear that many people face, when a snake crosses their path, wildlife respecting people will often ask themselves, “How do I know if this snake is dangerous or harmless?” As snake conservationists, we appreciate and respect the people that ask these questions, before they start swinging the shovel.
We wanted to write this article to help the average person identify some of the telltale characteristics of our indigenous venomous snakes, and direct them toward more comprehensive resources for identification in their own back yard. As always, we will include photos that can better demonstrate these characteristics as well, and give folks a basis for what these critters will look like.
We will cover some of the most commonly discussed attributes, that many people have heard of, and use as the occasion arises. However, before we get started, let’s take a look at the photos below, and see if you can pick out which snakes are venomous, and which are harmless….
So, do you think you know? Did you utilize all your knowledge regarding triangular heads, elliptical pupils, and color patterns? Are you ready for the answers? Here we go!
Photo 1: This is a harmless Northern Water snake. Did we fool you? Water snakes and some other species, do have somewhat triangular-shaped heads, and can even flatten them out more when threatened, making themselves look more intimidating.
Photo 2: This is a harmless Sonoran Shovel-nosed snake. It may sport the same red on yellow pattern as the venomous Coral snake, but this little snake makes its living eating insects, and could no sooner hurt a human, than it could sprout wings and fly. We can also tell that this snake is NOT a venomous Coral Snake, because it does not have a black head, and its red and black bands do not go all of the way around the body, like the Coral Snake’s do. If you look closely, you will notice that the black and red bands fade to yellow toward the belly of the snake.
Photo 3: This is a harmless Lyre snake. It has elliptical pupils, but poses absolutely no threat to humans.
Photo 4: Wow this one looks dangerous, right? Well, I hate to disappoint, but this is yet another harmless snake. It is a Hog-nosed snake, and one of the better fakers in the snake kingdom. They can flatten their neck, almost like a cobra, and even have some enlarged teeth in the back of their mouths. However, even though they are technically considered “rear-fanged venomous” these guys are very popular in the pet trade, and again, do not make a habit of, or have the proper equipment, to hurt people.
Obviously, there are some snakes in the U.S. that do pose a threat to humans, and we want to highlight them as well. However, we wanted first, to help you understand that many snakes are needlessly killed because they are confused for their “dangerous” relatives. With a little time and research, we are confident that you will be able to identify which snakes in your area can pose a threat to humans versus those that are not only harmless to people, but that are great to have around your home.
Hopefully the photos above have shown that there may be exceptions to every “rule”, but our intentions are not to cause more confusion. Despite the photos you just saw, many of the common identification tricks, are still “generally accurate”. We are not asking you to completely forget everything you thought you knew about venomous snakes, but are asking you to build upon your current understanding, by adding a little more knowledge to it.
Since there are vastly more harmless snakes in the United States than there are venomous ones, perhaps a good place to start, is by identifying the venomous ones. There are four general categories of venomous snakes in the U.S. They are the Copperhead, Water Moccasin (or Cotton Mouth), the Coral Snake and the Rattlesnake. Let’s take a quick look at these snakes, to get a general idea of what they might look like, when we see one in the wild.
Copperhead – Agkistrodon contortrix
Copperheads are fairly common in certain parts of the country, and because of their large geographic range, account for a fairly large percentage of venomous bites each year. That said, a Copperhead bite is very rarely life-threatening, when proper medical treatment is administered. Copperhead venom is relatively weak, compared to our other native venomous snakes.
Copperheads are generally identified as a medium-sized snake with an alternating pattern of tan bands separated by darker brown or rust-colored, hourglass-shaped crossbands. There are a handful of subspecies in the Copperhead group, so we’ve added the pictures below to help with identification.
Though we have better close-up photos of the snake below, this picture better captures what you might see in the wild, and also better highlights the hourglass-shaped crossbands we referred to earlier. We found this Copperhead on a trip to Kansas and Missouri. I hadn’t seen one in the wild, since I was a kid living in Arkansas, it was a very welcome reunion.
Below is a Northern Copperhead. Though it looks similar to the photo above, it becomes apparent that there can be some variation in color and pattern, and also in photography skills. Haha!
Last is the Broad-Banded Copperhead. Though it lacks definition in the hourglass pattern, you see that it still resembles its close relatives above. There is also one other subspecies of Copperhead, called the Trans Pecos Copperhead in Texas, which looks very similar to the Broad-Banded below.
Water Moccasin – Agkistrodon piscivorous
The Water Moccasin (also known as the Cottonmouth) is closely related to the Copperhead, and they are often found in the same geographical ranges. The Water Moccasin, however, is much more dependent on an available water source where it can catch some of its favorite food items like fish and frogs. They are typically darker in color and more muted in pattern than the Copperhead, but young Cottonmouths are vibrantly patterned, and then lose much of their contrasting pattern as they age.
One of the most difficult times people have with separating harmless from venomous snakes, occurs between Cottonmouths, and the wide variety of Water Snakes (refer to the first photo in this article). Both species love the water, and can be quite similarly patterned. Their head shape can look triangular – though the Water Moccasin’s head is much more prominently triangle-shaped, and they are both relatively heavy-bodied (almost fat looking) snakes. The one major difference, which we will cover a bit later, is pupil shape. While Water Moccasins, as well as Rattlesnakes and Copperheads all have elliptical (vertical – or cat eye-shaped) pupils, Water Snakes do indeed have round pupils. If you need this characteristic to help you ID the snake, however, you may be a bit closer to a potentially venomous critter, than you want to be, so please exercise caution. Zooming in with your camera or using binoculars can come in quite handy here.
The Water Moccasin has perhaps the most notorious reputation in the U.S. for being overly aggressive. There are more urban legends about these “demons” than any other snake. We’ve heard everything from them chasing people, to jumping out of trees on folks, and even climbing into boats to bite hapless fishermen. In our experience, and in the experience of our many snake-expert friends, this reputation is completely undeserved. These snakes are as likely to flee from humans as pretty much any other snake.
Below is a photo we took in Central Florida of a young Water Moccasin crossing the road, late at night. Check out that triangular head, and chubby body! Although we don’t encourage you to do this yourself, we really wanted to capture the iconic photo of this snake gaping, to show off its bright white mouth, that gives it its common name. Try as we might, the snake simply would not cooperate. We nudged it, prodded it, and I even put a little pressure on it with my foot, but the darn thing refused to show off its mouth, or jump up and bite me on the face. He just kept crawling away! Maybe he was just exhausted from biting his limit of fishermen that day. Or maybe all those stories you’ve heard, are just fish tales. Consider the source. *wink*
Below is a photo of an adult Western Water Moccasin. You’ll notice that it is much darker, and lacks much of the pattern of the young one above. This photographer was able to get the photo I was hoping for, and if you look closely, you can even see the elliptical pupil, differentiating it from the round pupil of the Water Snake.
Coral Snake – For more information, please see my other article on Coral snakes here: Red and Yellow Kills a Fellow
Although Coral snakes are elapids, and pack a potent venom, they are quite cryptic, are quick to avoid interaction with humans, and are the cause of very few venomous bites in the United States each year. Coral snakes can be identified as a relatively small, tri-colored snake, with a black head, and yellow bands that separate black and red bands. These bands will also continue all the way around the snake – not stopping at the belly, as with most of the harmless tri-colored snakes. Remember the rhyme “Red touches yellow, kills a fellow. Red touches black, is a friend to Jack.”, and you will be well on your way to identifying friend from foe in the U.S. However, please note that this rhyme will not always work in other countries.
Arizona Coral Snake – Micruroides euryxanthus
We took this photo in Southern Arizona. The snake was pencil-thin, and would not hold still for anything. Several of us surrounded this snake for a 15 minute photo-shoot, and despite being nose-to-nose with a “cold-blooded killer”, we were in no more danger than we would be in our own kitchens. They simply pose very little threat to humans unless picked up.
Eastern Coral Snake – Micrurus fulvius
The Eastern Coral Snake, has the same pattern sequence as the Arizona Coral, but can get a bit bigger, and is more likely to have black speckling on its red and yellow bands, giving it a less contrasting pattern.
Even if you do determine that you have found a Coral Snake, there are very few instances, when killing such an animal, is the best option. They are so incredibly shy, that accidental bites (instances where someone was not picking up or harassing the animal) are almost unheard of.
There are some 32 species of rattlesnakes, with even more subspecies. This family of snake is wide-ranging and diverse. They can differ drastically is size, habitat, color and pattern. However different they may be, rattlesnakes still have one defining characteristic in the United States, that is identifiable both by sight and sound. This of course, is the rattle. In the U.S., they’ve all got them. Babies have them, females have them, Pygmy Rattlesnakes have them, and so forth. The tail is your best indicator, in identifying if a snake is a rattler or not.
There are no rattlesnake/harmless snake hybrids roaming the hills that look harmless, but have the venom of a rattler. There are plenty of urban myths out there to suggest otherwise, but rest assured, they are not based in fact. We’ll go ahead and post several photos of various species of rattlesnakes, showing that they all have that one definitive characteristic in common.
The small rattlesnake below is a member of the Pygmy rattlesnake family. They do have small rattles, but they are certainly present.
The photo below, is for my friend Kathy, who lives in Florida, and was told that Pygmy Rattlesnakes do not have rattles. The answer is yes, they do have rattles. However, their rattle is even more diminutive than the snake, and may only be perceptible from a range that would put you closer than you want to be. These rattles are so small, that they are sometimes almost inaudible. Truth be told, we have seen a couple of photos of these critters that have had an injury or deformity that has left the snake rattle-less. This is the exception though, not the rule. If you come across a snake, and you truly think it might be a rattlesnake, utilize the identification strategies we will discuss below, to determine if it is harmless or not.
Now that we have more or less covered what our 4 venomous snake families in the U.S. look like, perhaps we can spend a little time looking into those characteristics that many people use, to help them identify a venomous snake from a harmless one in the wild.
Venomous snakes have a triangular-shaped head.
There are a couple of things to consider here. The first, which we have already discussed a bit, is that some non venomous snakes can also have triangular heads, leading to the needless killing of a harmless snake. Secondly, if you look at the Coral Snake, you will notice that despite its venomous nature, its head is completely rounded, like any other harmless species. This head shape characteristic is a good start to narrow things down, but we still need a couple of steps for proper and safe identification.
Let’s take a look at the photos below, and see if we can determine if they are safe or venomous.
One could argue that this snake has a triangular head. Your first impulse – especially since it is in a defensive position – should be to stop, give the animal a little space, and make a couple of quick observations.
1. Does the snake have a rattle on its tail? No – So it is not a rattlesnake.
2. What shape are the snakes’ pupils? Round – So in addition to secondary proof that it is not a rattlesnake, you are also safe to conclude that the snake cannot be a Water Moccasin or Copperhead either. However, Coral Snakes do have round pupils, so we’ll go one step further.
3. Is this snake black, red and yellow? No – So the animal is not a Coral Snake.
Your conclusion: This snake MUST be harmless!! This is, in fact, a harmless Gopher Snake.
Did you go through the steps from our last photo? What do you think? Let’s walk through it again.
1. Does the snake have a triangular-shaped head? Yes, from this angle it kind of looks like it does. We can’t make a positive ID yet, so let’s keep going.
2. Does the snake have a rattle on its tail? Unknown – We can’t see a rattle from this angle, and we don’t want to pick the snake up to find out, so we’d better keep going through our process of elimination.
3. What shape are the snakes pupils? Round – Now we know that this snake is not any of our North American pit vipers. We’ve eliminated Copperhead, Water Moccasin and Rattlesnake.
4. Is the snake black, red and yellow? Yes, it is. “Oh crap! Is this a Coral Snake?” Let’s ask one more question.
5. Does the snake have a solid black head, and black and red bands, separated by yellow bands? No. Thank goodness! This is not a Coral Snake.
Your conclusion: This snake is NOT venomous! It is actually a harmless, Red-sided Garter Snake.
Venomous snakes have vertical pupils
We already know that this statement is not completely accurate. There are some harmless snakes with vertical pupils, and the venomous Coral Snake has round pupils. However, since most snakes you will come across with vertical pupils will be venomous, it is another good characteristic to look into, when going through your process of elimination to identify that snake you just encountered. You already have a good start to the questions you will ask yourself, but let’s try to determine if the following snakes are venomous or harmless.
1. What shape are the snake’s pupils? Elliptical – This snake cannot be a Coral Snake.
2. Does the snake have a rattle? No – So this cannot be a rattlesnake.
3. Does the snake have a triangular-shaped head? Kind of rounded, but a little pointy – It is unlikely that this snake is a Copperhead or Cottonmouth.
4. Is the snake slender, or heavy-bodied? Fairly slender – It is again, unlikely that this snake is a Copperhead or Cottonmouth.
5. Does the snake have facial pits (all American pit vipers – rattlesnakes, Copperheads and Water Moccasins have them) between its eyes and nostrils? No – This snake is not a Copperhead or Water Moccasin.
Your conclusion: This snake is harmless. The photo above is a Night Snake.
1. Is the snake red, yellow and black? “I don’t know! You posted a black and white photo. You must be a complete moron.” 🙂
2. Does the snake have elliptical pupils? Yes. So it must not be a Coral Snake.
3. Does the snake have a rattle? “I can’t tell from this picture. Please refer to my moron comment above.”
4. Does the snake have a triangular head? Yes it does – This one could be venomous.
5. Does the snake have facial pits between its eyes and nostrils? Yes it does!
Your conclusion: This snake is definitely venomous! Exercise caution around this animal.
At this point, our primary question is answered. We know the snake has a bite that could very well be of medical significance. We will treat this snake, like any other venomous snake, regardless of its specific species.
If, however, you are still anxious to know what family it belongs to, now would be the time to go back to what we know about venomous snake colors and patterns.
6. Are Copperheads or Water Moccasins white? No they are not. – So by process of elimination, this must be some type of rattlesnake.
The photo above, is in fact, a white phase Speckled Rattlesnake. We used this photo because we really like it, but it also offers a great view of those facial pits we referred to earlier. The nostrils are quite small and nearly indiscernible in the photo. However, that large, circular pit between the eye and mouth of this snake, is unmistakable.
If a snake shakes its tail, it is probably a rattlesnake
While true that rattlers often shake their tails when threatened, this observation is not enough to properly identify a snake. There are actually several species of snake, that when bothered, will assume a defensive position, strike, and even shake their tails. We have seen this behavior in many species including Corn Snakes, King Snakes, Racers, Gopher Snakes, and Milk Snakes, to name a few. If you see this behavior, instead of assuming it must be a baby rattlesnake that hasn’t grown a rattle yet (we already know rattlers are born with one segment of a rattle), it is best to utilize the process of elimination method that we’ve been practicing above. After-all, do you really want to get rid of a King snake that may eat numerous rattlesnakes over the course of its life?
Below is a video of a Milk Snake exhibiting this very behavior, to give you an example.
Field guides and range maps
Two of your very best tools in determining if a snake is safe or dangerous, are field guides and range maps. The resources generally come with great photos or illustrations that you can use to help identify all of the snakes you might come across in nature. Even better, many of these guides are geographically specific, so you can find a resource that applies specifically to your state. It may not make sense to study up on the snakes of Mississippi, if you happen to live in Oregon. Finding these localized resources means much less studying for you, and who wants to anxiously thumb through 500 pages of snakes, while attempting to identify the one that is sitting three feet away from you?
Additionally, these resources can be great in helping you quickly eliminate certain possibilities. Range maps will tell you specifically which animals exist in your state. If you know from the start, that Water Moccasins do not live in your state, you don’t have to worry about the snake you are looking at, being one of them.
As an example, let’s say you live in Utah, and you find a red, black, and cream-colored snake. “Goodness, cream is kind of yellow, and I can’t remember that dumb red/black/yellow rhyme in the heat of the moment”. You really don’t want to risk having a Coral Snake in your back yard, right? Well, if you look at the range map below, you will see that Coral Snakes don’t live in Utah at all, so you needn’t ever worry about one being in your back yard. With a little more research, you’ll also find that Copperheads and Water Moccasins don’t live in Utah. Knowing that the only dangerous snake you might come across in Utah, will have a rattle on the end of its tail, just made your job much more simple!
You may want to go on-line, and buy a field guide specific to a region or state you plan to spend time in. One such example that we like to have on-hand, when we’re hiking in unfamiliar territory, is this one:
Field guides will often contain great information and details regarding other types of wildlife as well, turning your hike into an educational adventure.
However, please be aware that there are tons of free, on-line resources as well. We would suggest going to Google, and typing in “Snakes of your state“. For example, if you lived in Hawaii, you would type in “Snakes of Hawaii”, and then breathe a huge sigh of relief (unless your a snake fan, like us) when you open this link: You’re better off looking for snakes on Mars
If you do this, you will find an array of free, and readily available resources regarding the snakes that call your back yard home. As with any website or blog, not all sites are created equal. If this SnakeBuddies blog has taught you anything, it is that any dummy can publish an article on-line, and make it available to the masses. Don’t just pull up the first link you see! Go through a few of them, and utilize the one that is the most comprehensive and reliable.
What do I do, when I find a venomous snake?
Let’s say that you’ve found a snake, you’ve gone through our process of elimination exercise, and you find yourself looking at a definitively venomous creature. What do you do next? Your next move should depend greatly on the circumstance. Did you find the snake in your bathtub, or was it in the mountains? Was it entering a preschool, or was it swimming in a lake?
Secondly, put some thought into what options are available to you. Will you and others be safe, if you simply move away from the snake, or is it absolutely imperative that the snake be moved away from people? If the snake needs to be moved, is there a local reptile rescue or pest control company that will collect and relocate the animal, or do you have to do it yourself? We feel obliged to say, that dealing with any venomous snake, should be left to a professional, unless there is absolutely no alternative. Things can get crazy and super dangerous very quickly, when inexperienced people attempt to deal with snakes. If you live in a place where venomous snakes are relatively common, we encourage you to look up local snake relocation experts now, and keeping their phone numbers close by.
A very important consideration, when dealing with any snake, is whether or not the animal is protected under state, or even federal law. It is illegal in several states to kill, or even touch certain snakes. If you kill a protected species, don’t be surprised if instead of getting a hero’s welcome, you get slapped with a hefty fine.
Please note that far more people are bitten every year while trying to catch or kill a snake, than the people who simply walk the other way. If you must deal with the snake yourself, please do so safely, and without putting any part of your body within striking distance. Although we encourage you to always seek an alternative to killing the animal, if you feel like there is no other option, consider using a method that keeps you far from the animal. Also note that even after decapitation, a snake is not immediately “dead”. If you pick up a freshly decapitated head, you could still very easily be bitten. Please remember that snakes – even venomous ones – play a very important part in our environment and ecosystem.
Now that we’ve done some homework, and feel more confident in our venomous/harmless ID skills, let’s put this new-found knowledge into practice with a little quiz. We’ll post several photos below, and ask you to identify which are harmless and which are venomous. I’ll post the answers underneath. No peeking, and let us know how you did.
Alright, pencils down! Are you ready to see how well you did? Remember to post your scores, and which ones tripped you up. If you’re still having trouble, do a little more research, and you will get there.
Photo 1: Harmless – Round head and eyes, mean it’s not in the viper family, but the pattern is also wrong for a Coral Snake. It is a Ground snake.
Photo 2: Harmless – This Speckled Kingsnake has round eyes and head, and may occasionally feast on its venomous relatives.
Photo 3: Venomous – You can just make out this Sidewinder’s rattle in the background, but should have still noticed the elliptical pupils, big head, and those heat sensing pits.
Photo 4: Harmless – This Rosy Boa shares habitat with plenty of venomous critters, but the round eyes, and color pattern tell you it’s safe.
Photo 5: Venomous – Did you notice the heat pit between the eye and the nostril? The eyes, head shape and color pattern belong to the Copperhead.
Photo 6: Harmless – Nature loves to warn us of danger, by dressing its poisonous or venomous plants and animals in bright colors, but this Regal Ring-neck Snake is a faker, and is also a snake-eater.
Photo 7: Harmless – The Great Plains Rat Snake has a pattern similar to some rattlesnakes, but lacks the rattle, the elliptical pupils, and the triangular head.
Photo 8: Harmless – Not only is the critter non venomous, it is also non-snake! This is a Legless Lizard we found in Kansas. Notice the broken-off tail in the background?
Photo 9: Harmless – This little Central Plains Milk snake is beautifully patterned like a Coral Snake, but the red bands are touching black, not yellow (or white in this case).
Photo 10: Harmless – This fat body, triangular head, and ROUND eyes, belong to a Diamondback Water Snake.
Photo 11: Venomous – Not all Water Moccasins will gape at you, but you can still correctly ID them, if you look for their elliptical pupils and facial pits.
10-11 points: You know your snakes! Get out there, and put your knowledge to use.
8-9 points: Good job! You’re getting the hang of it. A field guide could be an excellent hiking companion, to help you with tricky snakes.
6-7 points: Hmmm – Someone was sleeping in class. Please re-read the blog, and practice up a bit more before going out to ID a snake.
0-5 points: Welcome to the world of birding! Snakes may not be your thing, and that’s ok. Let’s just stick to identifying creatures that can’t put you in the hospital if you misidentify them.
Thanks for stopping by and reading our blog! We realize that this article was entirely too long, but wanted to give you folks useful resources and guidelines. We feel better knowing that you will now have the confidence to know when it’s okay to get close to a snake, and when you should call for backup. Though this article was still far from comprehensive, you now have what you need to be safe. Misinformation and lack of education, can prove more dangerous than that Cottonmouth climbing into your boat. Take care, and be safe out there!
Educate. Inspire. Conserve.