Cottonmouth interesting facts
Snake Facts And Behaviors

31 Really Interesting Water Moccasin (Cottonmouth) Snake Facts

Cottonmouths are a snake from the south and eastern parts of the United States. They’re one of the first snakes that many of us encounter in the wild. But just because they’re so common, that doesn’t mean that there are many interesting water moccasin facts to discover.

For instance, did you know that they can produce babies without mating? Or that they’ll eat almost anything, from fish and tiny turtles to squirrels and other snakes—including other cottonmouths? Or that they have tiny sensors on their nose that can find prey using heat vision?

Interesting Water Moccasin Facts

We’ve found all the most fun facts about cottonmouths. There’s more information on breeding, their list of scientific names, what stresses them out, and much more.

1) Cottonmouths Have Cotton-Colored Mouths

Cottonmouth is the strangest name of any snake because their bite is anything but soft like a cotton bud. The name’s nothing to do with their bite. It’s related to their color.

The inside of a cottonmouth’s mouth is a cotton-like white. When they’re threatened, they’ll ‘gape,’ which is where they sit with their mouth open, staring at you. That’s when you see the color of their mouth and gums.

Aside from cottonmouth, they’re also known as water moccasins, obviously. It’s less clear exactly why the water moccasin is named after a kind of shoe. There are a few options:

  • Some Native Americans may have made shoes from their skin.
  • Native Americans may have made shoes in a pattern that’s similar to their skin.
  • It might be because they can move around quietly, like somebody wearing moccasins.

2) They Have Dozens of Nicknames

Since they’re so common across the U.S., cottonmouths have quite a lot of common names. You might have heard them called:

  • Agkistrodon piscivorus, their scientific name
  • Pit viper (which is the family of snakes that they’re a part of)
  • Water pilots
  • Mangrove rattlers, river rattlers, swamp rattlers or pond rattlers (they rattle their tails when threatened, just like rattlesnakes, but without the rattle)
  • Black snakes, black water vipers or black moccasins (when they get old, they lose their coloration and can become pure black)
  • Trap-jaws or snap jaws (because when you touch them on the nose, they’ll snap their jaws shut)

3) Their Scientific Name Means ‘Fish Eater’

Their scientific name, Agkistrodon piscivorus, is descriptive (like many scientific names). Scientists noticed that it loves to eat fish, so they gave it the name ‘piscivorus.’

This comes from the Latin ‘piscis,’ which means fish, and ‘voro,’ which means eat greedily. So, if you knew Latin, you could figure out that this animal loves to eat fish.

The first part of their scientific name (Agkistrodon) refers to a genus (big group) of snakes called pit vipers, which are found in North and Central America.

You’ll also see these Latin terms in the star sign Pisces, or in the words carnivorous or omnivorous.

4) There are Three Subspecies of Cottonmouth

Subspecies are different kinds of snake that are very similar but differ in minor things like pattern and location. So, you have three different cottonmouth subspecies, which are as follows:

  • Eastern cottonmouth, which is the ‘nominative’ subspecies. This means that it’s the ‘default’ version of the species in question. That’s why their scientific name is Agkistrodon piscivorus piscivorus. The eastern cottonmouth lives across the east coast, from Virginia south to Georgia.
  • Florida cottonmouth, which lives in Florida and the very south of Georgia. The scientific name is Agkistrodon piscivorus conanti.
  • Western cottonmouth, which has a wider geographic range than the other subspecies. You can find them as far north and east as Indiana, and as far south and west as Texas. The scientific name is Agkistrodon leucostoma.

In Alabama, Georgia, and Mississippi there’s an area where the three subspecies are mixed. If you find a cottonmouth there, they’ll share characteristics of all three snakes.

Agkistrodon piscivorus venom facts

5) They’re a Short Snake

Cottonmouths aren’t very long for a snake. They’re only between two and four feet long on average. However, you might find specimens up to six feet long out in the wild.

That’s because snakes don’t ever stop growing. They’ll grow to an average length within three or four years, and then keep getting longer, and longer, and longer. So, if you find one in the wild that’s much bigger than usual, it’s probably much older too.

Unlike many other species, the male is longer and heavier than the female. Both sexes have thick bodies for a snake of their length as ball pythons do.

6) What Color Are Water Moccasins?

Their coloration is quite variable. Their dark colors vary between dark brown and black. Their lighter colors vary between olive, brown and yellow, and their bellies are a light brown or even white.

Regarding pattern, they have bands running along their body. However, there are three subspecies of cottonmouth snake, so this doesn’t apply to all of them.

7) Young Cottonmouths Can Lure Prey

Young cottonmouth snakes have a yellow or green tail tip. They use it to lure in prey like frogs and lizards. This is called ‘caudal luring,’ where ‘caudal’ means related to the tail.

They’ll wiggle their tail around in front of a frog or a lizard. Because their tail looks a little like a lovely, tasty worm, the frog will hop closer, trying to catch it. The cottonmouth will keep going, reeling them in, until the frog or lizard is close enough for them to strike at.

8) They Lose Their Color As They Grow Older

As a water moccasin grows older, their coloration gets darker. Eventually, their top becomes a ruddy black, and their underside becomes whiter. You’ll see this in longer water moccasins, around four feet long, because these are the older specimens.

They’ll also lose their yellow/green tail tip. The older snakes can lose so much of their coloration that it disappears completely.

9) They Live Between 10 and 20 Years

Little is known about how old water moccasins get. Nobody has thought to study their lifespan, presumably because no scientists have been interested.

There’s a fact floating around that the oldest known water moccasin in captivity managed to live 24 and a half years, although it’s not clear who this snake was or where they lived.

On average, though, water moccasins live to between 10 and 20 years.

10) Where Do Water Moccasins Live?

You can find water moccasins across the southern United States. They live as far west as Texas, all the way to the east coast, and from Florida north to Illinois. They’re most common in the southwest, though. The warmer and wetter their habitat, the better.

They prefer to live close to water (hence the name), so you’ll find them in swamps, streams, lakes, and ponds. They’re semiaquatic, and spend lots of time swimming. The rest of the time they’ll spend basking near the shore, warming themselves up in the sun.

11) Cottonmouths Look Like Other Snakes

Water moccasins are venomous, but many lookalike snakes aren’t. There are lots of snakes across the U.S. that have similar markings to cottonmouths which aren’t venomous at all, including:

  • Eastern green water snakes
  • Brown water snakes
  • Red-bellied water snakes
  • Banded water snakes
  • Northern water snakes

Now, you might be wondering why this is so important. It’s because the unnecessary killing of non-venomous snakes is illegal under state law in many states like Tennessee, Georgia, and Texas.

In some states, it’s illegal to kill snakes at all without a permit (Tennessee, for example). So just because a snake looks like a cottonmouth, don’t kill it—besides, it’s unlikely to attack you anyway.

cool facts about water moccasin snakes

12) Water Moccasins Have Predators

Just because they’re a venomous snake, that doesn’t mean that they don’t have predators. The water moccasin is preyed on by many animals, including:

  • Birds of prey like falcons, horned owls, eagles, and hawks
  • Other birds like herons and cranes, which wade around in the same watery habitats as water moccasins
  • Alligators, where the two species share a habitat
  • Other snakes, including other cottonmouth snakes

When another snake attacks a water moccasin, they’ll use a self-defense mechanism called ‘body bridging.’ This is where the defending snake raises its midsection above the ground in a sort of loop. Then, when the attacker strikes, the defending snake will throw their body at them to knock them away.

13) They’re Unique Among Vipers

So, they’re related to vipers, and they’re venomous like vipers. But cottonmouths are the world’s only species of aquatic viper. They’re also the only venomous snake here in the United States that you’ll find in the water, too. So, no other snake ’s quite like them.

14) They Can Make Babies Without Breeding

If they can’t find a suitable mate, water moccasins will create young without breeding. This is called ‘facultative parthenogenesis.’

It’s a complicated process that involves splitting the chromosomes and recombining them differently. With this genetic material, the egg will grow just as it usually would.

The only difference is that there’s only the mother’s genetic material involved, rather than genetic material from both a mother and father.

Believe it or not, but quite a few different kinds of animal can create young this way. Plenty of other snakes do—in fact, the Bimini blind snake exclusively reproduces this way. However, it’s best for the offspring if they’re the result of regular breeding, as they’re more likely to thrive.

15) They’re Normally Ovoviviparous

When they’re not making babies without breeding, water moccasins are normally ovoviviparous.

This is an exceptionally long and scientific term that means they give birth to live young, but their young develop inside them, inside eggs. Oviparous snakes lay eggs, whereas viviparous snakes incubate young as mammals do.

It works like this. The female cottonmouth will fertilize her eggs, one way or another. They’ll then sit inside her reproductive tract as the snakes develop inside their eggs.

She won’t lay them at any point. This gives them an advantage because nothing can prey on them (mongooses and similar will happily eat snake eggs).

When it’s time for them to hatch, they’ll hatch inside their mother. The little tiny snakes will then make their way out of her cloaca, and slither off to live lives of their own.

Snake mothers don’t look after their young once they’ve hatched. They usually just lay their eggs and leave them, so cottonmouths are great parents by comparison!

16) Cottonmouths Brumate, But Not Alone

Most snakes brumate over the winter. Brumation is similar to hibernation, where the snake enters a period of low activity. They’ll stop eating, they’ll stop moving around, they won’t be mating, and they’ll be taking the winter off.

They’ll hide in dens like under rocks, in logs and hollow trees, anywhere that they’ll be safe. According to a paper in Comparative Biochemistry and Physiology, cottonmouths in northern states have to sleep deeper than those in the south because they need to conserve more energy.

But when they brumate, they don’t brumate alone. Some water moccasins sleep for the winter in dens, which they share with other venomous snakes. It’s odd.

It’s like they all agree that it’s for the good of everyone if they come together to help conserve a little more warmth. This is helped by the fact that snakes lose their appetite over the winter, so they don’t get the urge to fight each other as much.

17) They Come Out in Spring

In the springtime, once they’re done brumating, they’ll come out to start eating and mating again. However, this is unique to cottonmouths in the north.

Cottonmouths in the south don’t bother brumating for very long. That’s because it’s still warm enough that they can safely move around without getting too cold.

If it’s too cold, they’ll lose too much body heat and die. Not only that, but they won’t be able to digest when it’s too cold. But in Florida, a cottonmouth can happily keep active through the winter.

how venomous is the cottonmouth snake?

18) Cottonmouths Are Sort-Of Monogamous

Very few animals are truly monogamous. That’s because it’s beneficial to an animal to try and have as many offspring as possible. That’s easier if you have multiple partners across your lifetime, rather than just the one. Cottonmouths, though, are monogamous—in a way.

When it comes to breeding season (the beginning of spring), cottonmouths will pair up. They’ll then stay in that pair throughout the breeding season, the male fighting off any other males who want to mate with that particular female. They’re hoping that they can protect their female, who they want to have their babies so that they can carry on their genetic line.

Unfortunately, once the breeding season is over, the pair will ‘split up.’ When it comes to the breeding season next year, both snakes will pick a different partner.

19) Cottonmouths are Deadly

Cottonmouths are most definitely venomous. They’re one of the most venomous U.S. snakes. They use their venom to catch prey and immobilize it. The point of their venom is to incapacitate prey so that it can’t escape. They’ll then eat it while it’s dying, or once it’s dead.

Venom is made up of toxic enzymes that have an adverse effect on the body. There are a few different kinds of venom. Some attack the nervous system, which means that your brain can’t communicate with your body anymore, which stops you from being able to breathe.

Other kinds of venom destroy tissue, and some stop your blood from being able to clot, which has all sorts of adverse effects. According to a paper in the journal Toxicon, cottonmouth venom is made up of many enzymes including phospholipase A2, Asp49 and Lys49.

However, they’re unlikely to attack you. Most snakes are the same. Remember that they’re a fraction of your size, so they’re much more afraid of you than you are of them. They’ll only bite you if you consistently provoke them. So, if you find a cottonmouth in the wild, leave it alone.

20) They Use Heat Sensors

Water moccasins are what’s called a ‘pit viper.’ That means that they’re one of a group of snakes that have heat-sensing pits on their faces. These small pits sit right on their nose, between their nostrils.

These sensors help them detect infrared radiation, essentially heat, from about a yard away. Of course, this is for finding and striking out at prey.

According to the journal Nature vipers, pythons and boas share these heat-sensing pits. These ‘pit organs’ contain a thin membrane that picks up on the warmth of infrared radiation.

This membrane sits inside a tiny, hollow bone chamber that allows it to detect even very small changes in warmth.

21) They Have Huge Venom Glands

Cottonmouths have quite wide heads, especially when you compare them to a common pet like a ball python or a corn snake. That’s because they have venom glands, which create and store venom.

The bigger the snake’s head, the more venom they’re able to store. They also have quite thin necks, so the head stands out even more.

22) Their Venom is Hemotoxic

Cottonmouth venom is ‘hemotoxic.’ This means that the venom attacks and destroys red blood cells, which has all sorts of effects. First, it stops the blood from coagulating (clotting).

You’ll experience both external and internal bleeding, which is uncontrollable. So, you’ll bleed from your eyes, ears, and nose (and even your fingernails). It’s the internal bleeding that’s the worst, though, and the most likely to cause severe damage.

Unless you receive prompt medical attention, you’ll experience permanent muscle damage. Worse, it might result in needing your arm or leg amputated.

23) They Have Incredibly Painful Bites

A water moccasin bite is very painful. Like a viper, the cottonmouth has the most painful bite of any other kind of snake. Their bites create an incredibly strong burning sensation, which is because your tissue is breaking down.

Cottonmouth venom is designed so that it starts dissolving tissue immediately after you’re bitten. This helps them digest more quickly after they eat you.

Fortunately, you’re too big for them to eat. Unfortunately, you’ll still feel the pain of your skin and cells breaking down.

Is a water moccasin and a cottonmouth the same thing?

24) Even Young Cottonmouths Bite

When a young cottonmouth is born, they’re born ready for the world. They’re not like human babies, who need somebody to look after them until they’re old.

From the moment they’re born, they start producing venom. Their fangs aren’t huge when they’re young, but they still pack a punch.

25) They’d Rather Not Bite You

To create venom, a snake has to use quite a lot of energy. And all of their energy, they have to earn through hunting. If you didn’t know, it’s possible for a snake to completely run out of venom, either because they used it all, or because they’ve been ‘milked’ (which is a method of collecting snake venom without killing the snake, basically by draining out their venom glands).

That’s why cottonmouths see biting as a last resort. If they can scare you enough that you leave them alone, they don’t have to use any precious venom.

Instead, a cottonmouth is more likely to ‘musk’ at you. Musk is like what skunks produce, and it’s a horrible smell. A cottonmouth can spray this musk at you, as if they had a spray bottle, and get you covered in it.

26) Water Moccasins Are Afraid of Conflict

Rather than bite or musk, though, water moccasins would much rather try and escape. If they see somebody coming towards them, they’ll try and get away as quick as they can. How? By ‘jumping’ into the water.

Water moccasins hang out on logs or branches next to the water’s edge so that they can dive in for a quick getaway. They know that they can move quicker in the water than they can on land. And that you probably won’t follow them in any way.

27) They Attack When They’re Stressed

If you’re a snake owner, you’ll know full well that snakes tend to strike when they’re stressed for some reason. It could be because they’re hungry, or they’re trying to digest something and want you to leave them alone. Or it could be because you’re handling them too frequently, which is a significant stressor for captive snakes.

However, the same rule applies in the wild too. A team of scientists from the biology department at Pennsylvania State University found that snake bites are on the rise because of environmental stress.

They think that because the cottonmouth’s natural habitat is shrinking, and the temperature of the climate changing, this is stressing the snakes out—and causing them to bite more frequently when provoked.

As if that wasn’t enough, there are plenty more facts about water moccasins to learn. These don’t particularly fit into any of the sections up above, but they’re still fascinating facts that are worth learning and memorizing.

28) There Are Water Moccasin Myths

If you grew up in the South, you’ve likely heard stories about water moccasins. The most common one is the story where somebody’s out water skiing when they lose control and fall into the water.

They then find that they fell into what feels like a big ball of barbed wire. But it’s not barbed wire; it’s a writhing mass of cottonmouths, maybe fifty or a hundred of them. When the person’s pulled back into the boat, they’re covered from head to toe in bites.

Variations of the story include one where a group of young boys is going swimming when one shouts out “The last one in is a rotten egg!” and jumps in, only to find himself in that same big ball of cottonmouths.

Fortunately, neither story is true. Neither story could be true. Cottonmouths don’t nest together in water, deep or shallow. They’re solitary creatures, not social, so you’d never find them in big groups for any reason.

The origin of this myth might be from the garter snake. Garter snakes form something called a ‘mating ball,’ where dozens and dozens of males all fight to try and get the attention of just one female. But garter snakes aren’t venomous, and they don’t live in water, so there’s no danger of getting bitten to death by them when you’re water skiing.

29) They’re Omnicarnivorous

Water moccasins will eat almost anything—well, anything apart from leaves and plants. Like all snakes, they eat mammals and birds, as well as small amphibians (frogs and toads).

But aside from that, they eat quite a lot of fish, as well as small turtles that they’ll find in the water. They’ll hunt for fish in shallow waters, the closer to the bank the better.

They find it difficult to swim and hunt/bite at the same time, so they’ll try and corner a fish up against a log or the bank before going in for the kill.

But their diet doesn’t stop there. They’ll eat insects too like cicadas, snails, slugs, and caterpillars. All sorts of studies on cottonmouths have looked into what they eat, and the list is almost endless. They’ll even eat other snakes, including other cottonmouths.

30) Water Moccasins Have Keeled Scales

If you thought that all snakes have similar scales, think again. Water moccasins have a different kind of scale, called a ‘keeled scale.’ This is where each scale has a ridge running from top to bottom, i.e., from the end closest to the head to the end closest to the tail.

But why, apart from making them look different? Keeled scales help snakes grip to surfaces better. It’s like why we have fingerprints.

The ridges in our fingerprints help us hold onto things even when they’re wet and slippery. The ridges on water moccasins’ scales help them grip tree branches, rocks and anything else they’d like to climb on top of.

31) They’re Better Swimmers Than Other Snakes

Since they spend so much time in the water, water moccasins have become excellent swimmers. Most snakes, including full sea snakes, swim while entirely underwater. Non-aquatic snakes will do the same, but with their head poking out of the top of the water.

Water moccasins, though, are incredibly buoyant. They’re able to keep their whole body at water level, head, middle, tail and all. That’s important because they can’t breathe underwater, and this stops them from having to come up for air all the time while they swim.