Cottonmouth Snakes: Interesting Facts and Bite Information

The cottonmouth snake is a dangerous species in the animal kingdom and one to be reckoned with- a venomous lion of the water. Also known as the water moccasin snake, these vipers are fascinating creatures. I have gathered fun and interesting facts about the cottonmouth snake along with bite information and what to do if you are bitten.

Let’s start with its name. Note that this article will use both of its names- the cottonmouth and the water moccasin, interchangeably.

Fun Name Facts

The generic name – Agkistrodon piscivorus – is derived from the Greek words ancistro (hooked) and odon (tooth), and the specific name comes from the Latin piscis (fish) and voro (to eat); thus, the scientific name translates to “hooked-tooth fish-eater”.

The name “cottonmouth” comes from the white color inside the snake’s mouth which it flashes at intruders to scare them away. The second name, water moccasin, comes from its impressive ability to swim and dark brown or black coloring in its skin.

In addition to “cottonmouth” and “water moccasin”, this snake has many other nicknames, including swamp moccasin, black moccasin, snap jaw, water mamba, gapper, stub tail snake, and water viper.


There are three subspecies of cottonmouth snakes: western, eastern, and Florida cottonmouths. All of these subspecies are found in the Southeastern United States.

As you might have guessed, Western cottonmouth snakes are in the western region, eastern primarily east, and Florida cottonmouths are in Florida. However, the borders aren’t rigid and migration shifts do occur. It is possible to find a Florida cottonmouth snake outside Florida. It doesn’t even lose its core identity and spiral into a mid-life crisis. Way to be Florida Cottonmouth!

Where They Can Be Found

The following are states with reported populations of cottonmouth snakes:

  • Alabama
  • Arkansas
  • Florida
  • Georgia
  • The southern tip of Illinois and Indiana
  • Kentucky
  • Louisiana
  • Mississippi
  • Missouri
  • North Carolina
  • Oklahoma
  • South Carolina
  • Tennessee
  • Texas
  • Virginia
  • And some barrier islands off the coasts of the states they are found in

The cottonmouth snake is the only venomous water snake found in all of North America.

Birth and Lifespan

Cottonmouth snakes are ovoviviparous. This means they carry their eggs for five months and then birth live young, as opposed to most snakes which lay eggs and incubate them. A hatch can be anywhere from ten to twenty baby snakes.

While the cottonmouth can have its young year-round, they have their young generally within the same season, usually around the months of August or September. Like other species of snake, the mother will stay for the birth of her young but then will abandon them after the hatch to let them fend for themselves. Imagine having to stick it out for yourself as a newborn!

In the wild, the cottonmouth snake can live around fifteen to twenty years old. The oldest recorded cottonmouth snake lived in captivity and was twenty-four and a half years old.

Baby Cottonmouths

These baby snakes usually are ten inches long. The venom in a cottonmouth snake develops at a young age and can be very dangerous. If you see what might be a baby, treat it like an adult and stay at a safe distance.


Cottonmouth snakes are classified as a large snake. A mature adult is usually two to four feet in length. Male cottonmouth snakes are typically larger than their female counterparts, which is uncommon in snakes.

The size can vary from the three subspecies. The western cottonmouth is typically the smallest and the largest usually are the Florida cottonmouth- sometimes five to six feet in length. The longest cottonmouth on record is 74 inches, over six feet!


Cottonmouths may hibernate for several winter months depending on the climate. Generally speaking, they hibernate only in the northern reaches of the territory. In the more southern area of its range, the cottonmouth can be seen year-round.

Colors and Patterns

The color of the cottonmouth can vary. While they are young, juvenile cottonmouth snakes will have a lighter skin comprised of yellows, tans, olives, and all shades of brown, adorned with bold patterns, typically in the shape of bands across the body.

The underbelly is typically paler than the rest of the body. Interestingly enough, juvenile and young adult snakes will have a yellow-tipped tail that is used to lure and distract prey. We’ll cover that more in depth later.

As they age into adulthood, these bold colors will fade to darker tones overall. Most commonly, an adult cottonmouth snake will be black or brownish black with faded bands. The underbelly also undergoes a similar change to a darker brown or yellowish hue.

The tail goes from yellow as an adolescent to green for young adults till finally black to match the rest of the body.

Cottonmouth Snakes and the Water

Cottonmouth snakes always live near bodies of water, which is plentiful in the deep South. Semi-aquatic, the cottonmouth is an excellent swimmer able to completely submerge itself, strike prey underwater, and even swim upstream.

Typically, when they’re not laying in the sun to warm their cold-blooded bodies, the water viper can be seen swimming close to the water surface with its head just above the water, using its tongue and heat sensing pits below the eyes to sense potential prey.

Since swimming in the water cools down their body temperature, they spend most of their day in the sun and then hunting in the night.

Something I didn’t know is that the cottonmouth has a very buoyant body. This not only helps them swim for long periods of time but also means more of their body will be visible as they swim. This is a distinguishing feature from the look-alike nonvenomous water snakes that aren’t buoyant. 

Their Hunting Habits and Diet

The water moccasin’s diet consists mainly of amphibious creatures-  lizards, snakes (including smaller cottonmouths), small turtles, frogs, baby alligators, mammals, birds, and especially fish.

The water moccasin snake prefers to hunt for food in the nighttime when its prey is at the most vulnerable spot.

They’ll sit or swim near the waters edge till a potential target comes unsuspecting into range.

How they eat is interesting to me. Once the cottonmouth spots its prey, it will strike, bite, and release venom. What is intriguing and new information to me is they will then release the prey. Naturally, the prey will try to escape, whether it be a fish, lizard, or a frog. This allows the venom to travel throughout the body, killing it in the process.

The snake will give chase, keeping a short distance between itself and the prey. This viper then waits to devour the creature until the animal is completely dead. Then, as they swallow, they detach their jaw bone to enlarge the mouth and capacity to fit their meal. This is particularly handy for fish.

The adolescent cottonmouth will use its bright yellow tail to lure prey into striking range. Frogs usually fall victim to the tail waving slowly side to side above its body. 

Key Differences Between Cottonmouth Snakes and Nonvenomous Water Snakes

Whenever you see a snake in the water, it can be quite frightening. Especially since the venomous cottonmouth snake can look like other nonvenomous water snakes, it is important to be aware of these key differences.

Cottonmouth snakes have buoyant bodies. This was previously explained but remember that the cottonmouth can swim almost on top of the water while other snakes cannot.

Cottonmouth snakes most notably have different stripe patterns. The faded bands across their back that grow in width as they move to the underbelly sets them apart from the thin bands of a nonvenomous water snake.

Unlike nonvenomous water snakes which have rounded eyes, the cottonmouth has thin, slanted vertical eyes like a cat.

Another difference in their body shape is the head and neck. The cottonmouth snake will have a larger diamond shaped head and a smaller neck. Other water snakes will have very little difference from head to neck.

Water snakes will retreat, to water when possible, when threatened. Not the cottonmouth. They stand their ground and get as fearsome as they can look.

Predators of the Water Moccasin

This snake doesn’t go rampaging like it does without creating some enemies. Predators of the water moccasin include kingsnakes, alligators, snapping turtles, herons, cranes, and humans.

You may notice that this list overlaps with the food list from before. Water moccasin snakes run the risk of death to snatch up a tasty baby alligator, turtle, or bird.

When threatened, the cottonmouth will gape its mouth wide, flatten its body and on occasion, emit a strange odor to discourage predators. This penetrating odor has been likened to that of a billy goat or the common flood-plain weed, Placea.

All About Their Bite (And Venom)

Although they have a ferocious look, the cottonmouth snake will not usually attack unless provoked. The cottonmouth is usually talked up to be more aggressive than they actually are.

That being said, cottonmouth snakes will give two warning signs before they bite. First, they will open their mouth wide showing off the brilliant white mouth and then they’ll rustle their tail. This is an attempt to scare off other animals that might harm it.

As previously mentioned, the water moccasin snake has small hooked teeth, two fangs with venom, and a jaw it can detach to widen its reach to swallow larger prey or appear more fierce to intruders.

Snake’s venom has many components and can work in a few different ways depending on the snake. The cottonmouth’s venom is composed mainly of hemotoxins that break down blood cells. This means the blood is unable to clot causing large blood loss.

This loss of blood can be manifest both internally as well as through every orifice. Reports of cottonmouth bite victims bleeding out of eyes, ears, and nose are not unheard of. Gross!

What Do I Do If I Get Bit By a Cottonmouth Snake?

Cottonmouth snakes are not aggressive and prefer to be left alone. The best way to avoid a cottonmouth snake bite is to simply leave them where they are. That being said, the cottonmouth snake will not back down if provoked. Here’s what to do if you get bit by a cottonmouth snake:

If you are bitten by a cottonmouth snake, remain calm and quickly get to a safe area away from the snake’s reach, as it could strike again. Then seek immediate medical attention.

The most amount of pain will be directed at the point of the bite. While this pain varies for everyone, it generally is described as similar to a bullet wound. This pain can often mask the more serious effects of the spreading venom.

Do not panic, as panicking will increase your heart rate and subsequently the spread of the venom from the bite into the rest of your body.

Luckily, an anti-venom does exist which is known as CroFab, and this is used to treat this kind of pit viper bite. This anti-venom can only be administered by a doctor. Even when the anti-venom is quickly and properly administered, bites may still cause the loss of limb and permanent muscle damage.

Sometimes cottonmouth snakes will deliver to predators what is called a “dry bite”, or a bite without any venom dispersed in the victim. This happens when the snake is trying to conserve venom for later prey. A dry bite cannot be guaranteed and is hard to distinguish from a venomous bite at first, so take precautions.

Regardless of whether you think you have a “dry” cottonmouth snakebite or not, you need to see a doctor. Dry bites may still contain a small percentage of venom and may be less detectable. The longer you wait to be treated, the greater potential damage can be done.

Sadly, this is the case in the last fatal cottonmouth bite. In 2015, a man was bitten twice while wading in a river in Missouri. Because he did not immediately receive medical attention, he died the next day.

Related Questions

Are cottonmouth snakes and water moccasin snakes the same? Yes, these names are the two most common names for the Agkistrodon piscivorus and can be used interchangeably.

How many people are bitten by snakes in the U.S. each year? It is estimated that 7,000 to 8,000 people receive venomous snake bites every year. About five of those will end up being fatal.

Are baby cottonmouth snakes dangerous? The venom in a cottonmouth snake develops at a very early age and is still quite dangerous. Watch out for young or baby cottonmouth snakes!