Cottonmouth Vs Water Snake: Which One Is Completely Harmless?

Supriya Jain
Feb 29, 2024 By Supriya Jain
Originally Published on Nov 12, 2021
Fact-checked by Nishtha Dixit
Side view of a Cottonmouth snake
Age: 3-18
Read time: 7.9 Min

Snakes are present in many species across a wide range of habitats in the wild.

Some species are venomous and can instantly kill you with their bites, while some are completely harmless snakes and do not carry venom. But the problem is that how to differentiate between them and what to do if you confront a snake.

Cottonmouth and watersnakes are two banded snakes that have a range of bands on their bodies and look slightly similar. When one of these snakes is in front of you, how will you identify that the snake is harmful or harmless? Cottonmouths have their habitat in southern and southeastern Virginia, Texas, Indiana, Illinois and are native to the U.S. Do you know that water snakes do not carry venom and are nearly harmless, though if you are bitten by these animals, you will bleed a lot? So, let’s understand the difference between watersnake vs cottonmouth snakes, two banded snake species.

Afterward, you must also read about Florida water snakes and Garter snake diet.

How can you tell the difference between a water snake and a cottonmouth?

Most of the snakes look similar to each other in many aspects like length, shape, and bands. Just like every other animal is distinguished from other breeds of that animal by its characteristics, snakes are also distinguished by their characteristics.

Some snakes have triangular heads while some have round heads, some snakes have a narrow neck while some have an indistinguishable neck, some have round pupils like us while some have vertical pupils. All these characteristics lead us to tell the difference between different species of snakes.

A cottonmouth snake and water snake, both are found in almost the same colors - brown, black, and olive -  and in almost the same length. But they have a lot of differences which can help you to differentiate between them. A water moccasin has a pit-like face and a triangular head shape. These snakes have eyes similar to cats, meaning they have vertical iris, but the water snake has round iris. Cottonmouths have eye patches while water snakes do not. A water moccasin has a narrow neck which can be distinguished by its entire body, while a water snake’s neck is indistinguishable. Cottonmouths have a distinct pattern on their scales while water snakes have a lot of types of patterns on their scales.

Habits Of Cottonmouths And Water Moccasins

Cottonmouth snakes are also known as water moccasins. These snakes do not have a habit of fleeing at the first sign of trouble or threat from any predator or prey. At the time of trouble, it stands on the ground and opens its mouth widely. They show the predator their bright white mouth and warn them they are not going to back off.

The water moccasin is the only snake that exhibits this kind of behavior to handle the threat. A water moccasin also flattens its body and secretes some chemicals with a strong and pungent smell, which makes its behavior similar to skunks.

Normally a water snake, when moving in the water body, keeps their heads under the water. But these water moccasins keep their heads out of the water. You can also differentiate between these two types of snakes from this behavior also. A cottonmouth snake is very aggressive in nature but it attacks humans very rarely. Water moccasins hibernate during extreme cold seasons and become active once again on the onset of a bit of warm weather.

Characteristics Of Water Moccasins And Cottonmouths

Cottonmouths are native to southern parts of the United States, mainly the southeastern areas. These snakes belong to the species of pit vipers. Do you know that water moccasins are the only semi-aquatic pit vipers in the world? Also, these snakes are the only venomous species of water snakes that are found in North America.

Cottonmouths belong to the family of Viperidae. The members of this family have heat-sensing pits between their nostrils and eyes which help them to find their prey easily with the slightest variation of temperature. These pits can be found in snakes including rattlesnakes, copperhead snakes, and water moccasins.

A cottonmouth snake has white markings around its mouth which gave it its name. Also, this snake has a white and bright mouth. These snakes are venomous in nature and can paralyze you, if bitten with their venom. Water moccasins have a pale belly as compared to the rest of the body. Its body is covered in scales along with distinctive keels. It has a muscular body and a black tail. The juveniles have a yellow-colored tail. The yellowtail turns black with age and time.

Cottonmouth And Similar Looking Harmless Species

As almost all species of snakes look similar with a slight difference in their size, shape, length, colors, and scales. There are some snakes that look a lot similar in shape, length, and structure to the cottonmouths. A northern water snake is often misidentified as a cottonmouth snake.

A cottonmouth snake is venomous, but the northern water snake is nonvenomous, in fact, they do not have any kind of venom in their body. Hence, their bites won't have many effects. The body of a water moccasin fades to black near its tail while a harmless northern water snake’s body has the same color near its tail as its whole body.

The skin pattern of a brown water snake is somewhat similar to the skin pattern of a cottonmouth snake. A brown water snake, like the other water snakes, is a nonvenomous and harmless snake, but the cottonmouth snake is very harmful and poisonous. You can differentiate between them by the color of their tails. Cottonmouths have black tails while brown water snake does not.

A plain-bellied water snake also looks similar to a cottonmouth snake in some cases. But they can be easily differentiated. A plain-bellied water snake which is a harmless snake has no pattern on its skin, it is plain brown to reddish-brown in color. A cottonmouth snake has distinctive patterns on its skin to differentiate it from other snakes.

Distinguishing Water Moccasins And Cottonmouths From Non-Venomous Snakes

You are probably thinking why is it necessary to distinguish venomous snake species from nonvenomous ones, just be careful of both of them because all snakes are dangerous. But did you know that a lot of harmless non-venomous snakes which are misidentified as venomous cottonmouths are killed without any cause?

Humans kill them to protect themselves without realizing that this snake will not cause any harm to them. The most common victim is a northern water snake.

If you see snakes moving in water with their heads inside the water then it is not a harmful snake, it is just some innocent water snake that will not harm you, it eats fish not you. If the heads of the snakes are out of the water then this is water moccasin, meaning a venomous cottonmouth. You can also identify them with the shape of their heads, water moccasins have a triangular head shape and the harmless water snakes have round heads. You can also differentiate a cottonmouth by its pupils, vertical pupils mean a cottonmouth and round pupils means safe water snake.

The most important distinguishing feature between venomous snakes and harmless non-venomous snakes is the pattern of scales. The non-venomous snakes have double rows of scales after the anal plate while the venomous snakes have a single row of scales generally after the anal plate.

Banded Sea Snake underwater

Which is more dangerous: cottonmouth or water moccasin?

Did you know that there are no venomous snakes in Will County? When it comes to more dangerous snakes of the two species, the cottonmouth snake is the only venomous water snake that is native to North America, whereas water snakes are believed to be largely non-venomous.

Cottonmouth snakes are semi-aquatic snakes that attack humans only when they are threatened. The cytotoxic venom that cottonmouth snakes possess is quite potent and as a result, these snakes are feared by people present near their natural wild habitat. But their venom is actually not as potent as rattlesnakes. The only symptoms that you may experience on a water moccasin bite are severe pain and swelling.

Treating Their Bites

The cottonmouths are rarely dangerous for humans. They will bite you only when you threaten it. If they bite you then they can be very dangerous for you, you can probably get paralyzed by their venom. The venom of cottonmouths can also cause internal bleeding, though the wound is not fatal. This is a medical emergency and you need to seek medical help as soon as possible.

It may take some time to reach medical help, but till then you have to take care of the person who has been bitten. Make sure that the victim does not move much, make its movement as low as possible. This is because the movement can increase blood flow in the body which can lead to the spread of venom from the bite to the entire body.

You need to remove any accessories which are close to the wound because the wound will swell the area. Once the area is swelling, it will be difficult to remove them and may lead to future pain and suffering. You can also use a pump suction device to remove the venom from the bitten area if that is available. You must follow the instructions carefully while using this device.

Here at Kidadl, we have carefully created lots of interesting family-friendly facts for everyone to enjoy! If you liked our suggestions for cottonmouth vs water snake then why not take a look at coral snake look alike, or Water Snake Facts.

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Written by Supriya Jain

Bachelor of Commerce, Master of Business Administration specializing in Marketing

Supriya Jain picture

Supriya JainBachelor of Commerce, Master of Business Administration specializing in Marketing

As a skilled member of the Kidadl team, Shruti brings extensive experience and expertise in professional content writing. With a Bachelor's degree in Commerce from Punjab University and an MBA in Business Administration from IMT Nagpur, Shruti has worked in diverse roles such as sales intern, content writer, executive trainee, and business development consultant. Her exceptional writing skills cover a wide range of areas, including SOP, SEO, B2B/B2C, and academic content.

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