Northern Water Snake Care Sheet

Northern Water Snake

Scientific Facts

Common Name:Northern Water Snake
Scientific Name:Nerodia Sipedon
Life Span:Up to  9 years
Mass:158.9 g to 408 g (Females), 80.8 to 151 g (Males)
Length: Up to 140 cm
Clutch Size:Average of 8 per litter
Habitat:Aquatic Habitats (Lakes, ponds, streams, rivers, marshes, canals, ditches)
Country of Origin:United States

Physical Description

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The Northern Water Snake is considered among the largest snakes present in North America. The largest ones can even grow up to four and a half feet in length. These snakes usually have a heavy body with a large head. This means an equal proportion between the body and the head of the snake.

They are usually found in different colors, though the majority feature bands of black, brown and dark green, even though they may also have a reddish or sandy color on their bodies. As these snakes grow older, their color also tends to darken. The older Northern water snakes usually have a body that is almost completely black. 

The back and sides of their bodies feature a series of square blotches that alternate with each other. These blotches then merge to create bands. The adult snakes may appear black or solid brown, most especially when dry. The belly of these snakes is usually white, orangish or yellowish, with some dark half-moon-shaped black edges. The young ones have reddish-brown saddles on a brown, tan, or gray background. In terms of size, the males are usually smaller compared to females. 

Northern water snakes are also described as being heterothermic, which means that they love basking under the sun in order to regulate their body temperature. 

Natural History

As these snakes live by the water, they live up to their common name. They prefer the water, but will also transport themselves or hunt in fast-moving creeks. They love using muskrat homes, beaver lodges, and brush, both living plants and dead piles along the water. 

They also love using man-made structures, including waterside structures such as bridge supports, docks, causeways, rock dams, and spillways. When they are disturbed, these water snakes dive into the water quickly, submerging for a few minutes before they resurface to check on what is happening, and seeing the danger. If they still feel threatened, they will dive down again and stay beneath for a long time. 


This snake was originally described by Carolus Linnaeus as Coluber Sipedon back in 1758. It was based on a certain specimen which was sent to him from North America, by a certain Pehr Kalm. In 1953, Schmidt restricted the type of locality to the vicinity surrounding New York City. 

In 1977, Rossman and Eberle changed the generic name of this snake from Natrix to Nerodia. Until that year, most authors of literature in Virginia used the genus Natrix for these snakes. However, in 1900, Cope included Sipedon as a subspecies of N. Fasciata. Authors that followed have used this present nomenclature. Under this species, four subspecies have been identified. 

Northern Water Snakes Subspecies

There are generally four subspecies of Northern Water Snakes that are recognized currently:

Lake Erie Water Snake (Nerodia Sipedon Insularum)

These species are usually found on a group of islands located in Western Lake Erie, as well as the Marblehead peninsula in the state of Ohio. This subspecies is once threatened but is now thriving in its habitat. It is characterized in a soft gray color with some partial band patterns. This snake is medium in size, with females that reach up to 3.5 feet, or 1 meter in length.

Carolina Water Snake (Nerodia Sipedon Williamengelsi)

This subspecies is usually found in North Carolina, especially in both the mainland coast of the Pamlico and the Core sounds counties and the Outer Banks Islands. 

Midland Water Snake (Nerodia Sipedon Pleuralis)

This subspecies is typically found in Northern South Carolina and Georgia, through Eastern Louisiana, Alabama, Illinois, and Southern Indiana, and to the Eastern part of Oklahoma. 

Northern Water Snake (Nerodia Sipedon Sipedon)

These snakes are usually found in the Northern Maine and North Carolina, Northern Indiana, Illinois, West to Central Tennessee, West to Eastern Colorado, Minnesota, Ontario, and Quebec, Canada.

Similar Species

Northern Water Snakes are usually mistaken with other species of water snakes, including the broad-banded water snake, and cottonmouth water snakes. Broad-banded water snakes have crossbands that run through their entire body, with a light and black line that runs from the corner of the eye in a diagonal direction right to the corner of its mouth. 

On the other hand, cottonmouth water snakes are naturally darker, with a heavier body and a facial pit that is located in between their eyes and nostrils. 


Northern Water Snakes are usually found in different states within the United States. They are often considered as among the most frequently encountered snakes nearby the water in the state. Even though they are quite abundant along wetlands and rivers, they adapt well to man-made environments, readily colonizing small ponds and lakes. They also love utilizing concrete and rip-rap structures. 

These water snakes are distributed in the northern half of the country, while another subspecies, the Midland water snakes are distributed across the southern half.  There are many animals in the mid-state that appear to be intermediate in between these subspecies. 


Northern Water Snakes usually range from 244 to 55 inches (61 to 140 cm) in size. 

Colors and Patterns

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The dorsum of the body and tail come with several closely spaced, complete, and dark crossbands anteriorly which break up at around the mid-body, creating a series of alternating, rectangular, and lateral blotches. These blotches alternate in contact or separated by a single scale. 

The body color varies from brown to gray, with a variety of yellow, red, or white amounts of dorsal blotches and crossbands varying from reddish-brown to solid black, with black borders. Two irregular rows of dark half-moons are also present on the ventral scales, with half-moons varying from reddish and tan to all black in the center with some black borders.


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These water snakes are usually found throughout the eastern half of the United States, particularly in the Midwest and Northeast. They also love a wide variety of aquatic habitats. They are also often seen basking beneath rocks, and love slow-moving or standing water nearby areas where they can also bask under the sun, including vernal pools, ponds, and lakes. Beaver lodges and muskrat houses are also good places to locate the Northern Water Snakes, as they love hiding among the plant stems and sticks. 

Life Cycle and Lifespan

Northern water snakes usually mate right after coming out of brumation, typically from late March to April. The female snakes give birth between late August and the earlier part of October to live young. They usually have 12 to 36 young snakes at a time. Their lifespan is usually nine years in captivity. In the wild, their lifespan is unknown.


Northern Watersnakes are usually active at daytime and nighttime. They are usually seen basking beneath rocks, brush or stumps. At daytime, these snakes hunt among plants at the edge of the water, searching for small fish, worms, frogs, crayfish, leeches, small birds, salamanders, and mammals. 

At nighttime, they concentrate on minnows, as well as other small fish that are relaxing in shallow water. They also hunt using their sight and smell. They are also commonly found in their range, from where they dive into the water at any slight disturbance. It is also quick in fleeing from danger. Still, when captured or cornered, it usually does not hesitate in defending itself. The bigger snakes can cause a painful bite. 

These snakes are social only at fall and spring, right after overwintering. They are typically found in groups at different basking sites. They love coiling together. Most of the time, they are solitary animals, most especially during the warmer months. It is also common to find these snakes on overhanging branches, beaver lodges, walkways, dried cattail stems, as well as other shallow water areas. 

Northern water snakes possibly communicate using touch and smell. They also tend to use their sight and detection to vibration to locate their prey.


Northern water snakes love a variety of diets depending on their species and habitat. Some of the snakes eat small mammals, invertebrates, amphibians, and fish. They eat almost any animal that they encounter. For this, they are regarded as a beneficial species due to their preference for eating pests such as mice. 

They also prefer hunting at night in the water, catching small fishes and minnows. Another interesting aspect about these snakes is that even though they are nonvenomous, their bite features anticoagulant substance that prevents the bite wound from healing completely.


These water snakes usually mate around April through June. They are described as ovoviviparous, which means that they bear to live young. They do not lay eggs, just like other snake varieties. Rather, the mother carries the eggs in her body, giving birth to free-living youth. Each of the young ones is 19 to 23 cm in length. 

A female snake can lay as many as thirty young at any given time. The average, however, is eight. These young are usually born between August and October. The mother snakes do not usually care for their young, which means that as soon that they are young, they are usually left on their own. 

The young snakes grow quite fast during the first couple of years, doubling in terms of size as they reach two years old. This is also the time when they become sexually mature. At three years onwards, these snakes continue to grow at a slower pace. As they continue to grow older, they are also observed to become darker in color. Snakes that are kept in captivity are known to survive even up to ten years.


hibernating snakes

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Northern Water Snakes usually travel distances from their original water habitat, showing up in extremely different conditions. In some cases, they are even found below railroad tires and other areas. In winter, they often bromate far from water. Quite interestingly, it is not unheard of for Northern Water Snakes to bromate with other species, including the copperhead, black rat snake, and the timber rattlesnake in habitats where they are usually found.

Development and Reproduction

Male Northern Watersnakes are capable of reproducing when they reach 21 months old. The female snakes, on the other hand, start to breed when they reach three years old. They tend to produce a single litter every year. Most of the reproduction happens while in, or close to their sites of hibernation during the mid-April to mid-June. The latitude and temperature may impact the variation of reproduction during these times. 

During the breeding season, a male approaches a female, rubbing his chin along her back. A spasmodic jerk occasionally happens. Then, he twines his tail around the tail of the female, bringing their cloacal openings in contact. Typically, only a single female copulates with a female. On specific occasions, there may be two. 

The gestation may last between 3 and 5 months. The young snakes are born alive, which means that these snakes do not lay eggs, from July to September. The litter also varies in size. Bigger female snakes usually have larger litters. 

Female snakes usually protect and nurture their young right before they are born. However, after they are born, young snakes become independent, and they are already capable of caring for themselves and hunting their food. 

Possible Danger to Humans

Northern Water Snakes are nonvenomous by nature, which means that they are harmless to humans. However, since they look similar to the venomous cottonmouth, they are often killed as a result of mistaken identity. 

These types of water snakes can be distinguished easily based on their morphological traits. The Northern water snake has a longer and more slender body with a flattened heat which features the same width as its neck. It also features round pupils. They also do not have heat-sensing pits. 

On the other hand, the cottonmouth snake has a relatively fatter body, with a wedge-shaped head and prominent venom glands which are wider compared to its neck. It also features cat-like pupils, along with heat-sensing pits located in between the eyes and the nostrils. 

Reputation – Aquatic Predators

Some people notice a “stick” floating around the lily pads, suddenly moving afterward. A group of veterans tried casting a bait near the lily pad, but it did not scare the presumed “stick” away. Rather, it waited fearlessly until the cast frightened a small frog instead. Then, the stick, which is actually a water snake, became active and turned into an aggressive predator. This is an observation that earned the reputation of northern water snakes as aquatic predators. 

These snakes rightfully deserve their aggressive reputation. They are often observed to approach anglers in boats or on land. They also tend to defend their resting locations. While they are hunting for food, they also do not shy away easily from people. As such, it is often recommended to stay from a distance and retreat when approached by this snake. 

It is often not a good idea to hold water snakes, let alone, keep them as pets. They have very powerful jaws that can easily inflict a serious bite. If cornered or handled, it tends to strike repeatedly at the enemy. At worst, the bites of these snakes bleed seriously, which comes as a result of the presence of an anticoagulant quality found in the saliva of these snakes. 

These snakes play a vital role in maintaining balance in nature. This predator is fascinating to observe from a distance, as they become aggressive in foraging for food, basking in the sun, swimming under and across the watery areas, or crawling around the roots in its habitat. 

Snakes are, by nature, reptile. The characteristics of these snakes include having an internal skeleton that is supported by their backbone, with scaly, dry skin. They breathe with lungs, though they cannot regulate their body temperature. They reproduce live young. 

Activities During Summer

From April to October, you can observe these water snakes in different areas. At daytime, they can be observed basking under the sun on rocks and brush or hunting among the water edges of plants. Their menu at daytime includes worms, frogs, salamanders, crayfish, small birds or bird eggs in nests. 

At nighttime, they tend to use darkness as cover, while hunting minnows and injured, or slow-moving fish. Their romance starts when the warm temperatures become stable, which means that mating can finally take place. 

These northern water snakes give birth to actual live young during August and October. The young are brighter in color, usually more vivid than their parents. The mothers do not care for their young, as the newborns know how to care for themselves, even hunting their food. 

This phase of their life is usually the most dangerous, which is why mortality among Northern Water Snakes are usually the highest among juveniles. They are usually eaten and preyed upon by bass in ponds, as well as other bigger sport fish in lakes. 

Even as they reach adulthood, these snakes still have a lot of predators including raccoons, hawks, great blue heron, foxes, as well as snapping turtles. When they feel threatened, they tend to vigorously defend themselves by biting repeatedly and striking, while releasing musk and excrement. 

Another dangerous thing about Northern Water Snakes is crossing roads during migrating and breeding season, especially when traveling from one source of water to another while searching for food, mate or a place to hide. 

If these snakes are successful in avoiding cars and predators, they can live for more than five years. When the temperatures go low, and the frost arrives, these snakes look for a winter den. These sites may be burrows, rock crevices, pockets deep in the root systems, as well as other sheltered places near their habitat during the summer. During the warmer months, they may move out to other habitat locations. 

Conservation and Threats

The Northern Water Snakes species is quite stable. Still, it is facing habitat loss. On top of that, these snakes are killed occasionally simply because they are mistaken for other dangerous snakes, such as water moccasins or the venomous cottonmouth. 

Populations of Northern Water Snakes are currently declining surrounding areas of urban development as a result of habitat loss. In other areas, they also fall victim to people who are making a “sport” out of shooting them. 

This calls for the need to encourage public education regarding their real identification, thus lessening the killing of people who mistake them as water moccasins or the venomous water snake that looks like them. Nerodia Sipedon usually lives in freshwater, as well as in brackish wetlands, so long as they can still find food and good hiding places. 


A northern water snake has many predators, including raccoons, birds, foxes, snapping turtles, opossums, other snakes, and even humans. They vigorously defend themselves when they are threatened. When picked up by an animal or human, it will repeatedly bite, while releasing musk and excrement. The saliva of these snakes has a mild anticoagulant, which may result in the bite bleeding even more. This substance, however, poses a little risk to humans.

Northern Water Snakes and Ecology

This water snake’s diet mainly consists of different small-sized fish, toads, frogs, and salamanders. It is almost always near to water, or in the water. They usually love slow-flowing water, though they can swim easily and move through the water despite strong currents. When threatened or disturbed, these snakes can be really aggressive, striking out fast. Even though these water snakes feed on fish, they usually have little impact on the activities related to sport fishing. They usually eat small, and slow-moving, even injured fish. 

These water snakes were killed before under the thought that they also ate game fish. However, reality dictates that they even improve fishing because they eat dead or dying fish, thus preventing the possible spread of diseases among fishes. This further reduces the overpopulation of fish, and offering food for game species, with the large game fish-eating young water snakes. 

As predators, these Northern Water Snakes help in controlling the populations of the animals that they consume. Snakes, however, are being preyed upon themselves. Their newborns are defenseless and are eaten by animals that range from fish and large frogs, and even other snakes, mammals, and birds. The adult snakes, on the other hand, are also eaten by birds and other predatory mammals. 

Fun Facts about Northern Water Snakes

Here are some interesting facts about Northern Water Snakes:

  • Northern water snakes are the most common varieties seen in brackish and fresh waters in the Chesapeake areas.
  • These snakes are capable of staying underwater for an hour and a half straight without coming up the surface for air. 
  • These snakes are not venomous. Still, they may bite when threatened. As such, it is often best to stay at a safe distance, just in case.
  • Northern water snakes are often confused with the cottonmouth snakes, which are known to be venomous. These two types of water snakes can be distinguished, with the Northern Water Snake having round pupils, as well as a double row of scales under the tail. 
  • These snakes are well-adapted to their aquatic habitat. They are also excellent swimmers, patrolling the water with just their head right above the surface. 
  • Their prey is located by a combination of smell and sight, with the snakes detecting motion using their vision, while also having a sensitive sense of smell. 
  • The young Northern Water Snakes fall prey to various animals. The mammal predators include skunks, minks, and otters. Their avian predators include herons, hawks, bitterns, egrets, and rails. Other snakes also prey on these watersnakes, including the northern black racer, and the eastern ratsnake. 
  • These snakes emit a powerful musk from their cloacal glands and can be aggressive and fierce, biting and chewing their attackers. 
  • These water snakes usually conceal themselves in covers of vegetation. In cooler temperatures, however, they bask under the sun by sitting on floating logs, rocks, and branches overhanging water. Any slight disturbance will send these water snakes back to the water fast. When they feel threatened, they can also stay submerged for long periods of 60 minutes and more. the month of October, these snakes will start to group to go through brumation. Unlike actual hibernation where the animals are usually asleep, snakes going through brumation stay awake, though inactive. 
  • Aggregation refers to the grouping of snakes. They prefer winter den sites, including muskrat burrows, earthen dams, vole tunnels, and beaver lodges. From time to time, these snakes establish winter areas in upland locations. These snakes usually surface from their dens around April. 

Other Notes about Northern Water Snakes

This snake is also known by other common names. For example, in Virginia, they are known as a water snake, common water snake, water moccasin, dryland moccasin, a brown-banded water snake, the banded water snake, and moccasin.  At times, the difference in their common name has something to do with the location they are in.

Where to Get One?

If you are planning to care for a Northern Water Snake as a pet, it is recommended to visit a reptile breeder. It is rare to find this variety of snake in usual pet stores.

How to Care for Northern Water Snake as Pet

In captivity, Northern water snakes can be maintained easily. Even though fresh drinking water should be present at all times, care is important to keep the captive environment dry. These snakes are extremely vulnerable to scale rot, which is a bacterial infection caused by the incapacity to dry out completely. Even though some topical solutions can be bought, it is best to prevent scale rot from happening. 

There are different types of substrate that you can prepare for this species, such as dry mulch, rubber backed commercial carpet. It is also vital to prepare an overhead light for your snake. These snakes spend a huge amount of their time basking at various levels beneath the heat bulb, enjoying the benefits of the full spectrum rays. It is also important to install a strong branch that can support an adult-sized snake. Northern water snakes enjoy a diet of frogs, fish, and salamanders. It is important to keep the living environment of your snakes clean. 

FAQ Section

Are Northern Water Snakes Dangerous?

Northern water snakes are non-venomous. This means that they are harmless to humans. However, they are superficially similar to the venomous cottonmouth in appearance. As such, they are unnecessarily killed due to mistaken identity. 

Do Northern Water Snakes bite?

Adult Northern Water Snakes have dark bands. Because of this appearance, they are usually mistaken as the venomous cottonmouths or copperheads. However, Northern Water Snakes are not venomous by nature. Still, they can be agitated. When this happens, they usually flatten their bodies and bite. 

How do you identify a Northern Water Snake?

In terms of appearance, Northern Water Snakes have back dorsal, or back bands which are located on the anterior part of the body. This can also change to alternating back and side blotches. Their belly scales, on the other hand, usually have dark half-moon shaped marks on them. 

Are Northern Water Snakes aggressive?

As a water snake, Northern Water Snakes can be aggressive. When they are handled, they may tend to hiss, or even bite as a defense. As such, some do not consider them as good options for pets. They could also be aggressive when approached, even when they are not touched. 

Are Northern Water Snakes Protected?

In areas wherein the presence of Northern Water Snakes is abundant, they are not protected throughout most of the location. However, in the state of Georgia, in particular, they are protected accordingly. 

Do Northern Water Snakes lay eggs?

Most snakes under the water snakes category, Northern Water Snakes included, are described as live-bearers. This means that even though the females do not lay eggs, they give birth to live young. This is particularly true among snakes found in most parts of the Eastern United States.

How long do Northern Water Snakes live?

Northern Water Snakes are known to reach up to 9 years in captivity. Their average lifespan in the average is quite unknown. 

How big can Northern Water Snakes get?

Females are generally longer and heavier than males. They also tend to grow much faster. These water snakes can grow large, usually reaching about 5 feet or 1.5 meters. Other species also average about 3 feet in length.

What do Northern Water Snakes look like?

These snakes usually have dark, brownish, grayish or tan colors. The sides and backs feature a series of square blotches that alternate with each other, even merging to create bands. The adult snakes may appear black or solid brown, particularly when dry. The belly is typically white, orangish, or yellowish, with dark half-moon-shaped black edges.

Where do Northern Water Snakes live?

Northern water snakes are usually found in the Southern part of Ontario, as well as the northeastern part of the United States, from Kansas and Nebraska in the west, to the Atlantic Coast. They can also be found as far south as Southern Missouri and North Carolina. 

What type of habitat do Northern Water Snakes need?

Northern water snakes prefer different aquatic habitats, including streams, rivers, lakes, sloughs, bogs, ponds, marshes, as well as impoundments. They love open areas which offer different spots for them to bask under the sun while enjoying still waters. They may also move to land, particularly the young ones, though they never really stray far away from their aquatic environment. 

How do Northern Water Snakes reproduce?

Male Northern water snakes can start reproducing as soon as they reach 21 months old. The females, on the other hand, start to breed when they reach three years old. They can produce a single litter every year. Most of the reproduction happens while in or close to their hibernation sites, that is, between mid-April and mid-June. The latitude and temperature may result in variation in these times. 

How do Northern Water Snakes behave?

Northern water snakes are social only after overwintering, during the fall and spring seasons. They are usually found in groups, together at basking sites. They usually coil together. They are mostly solitary animals, particularly in the warmer months. 

Can Northern Water Snakes communicate with each other?

The possible form of communication between Northern Water Snakes is through touch and smell. They can also utilize their sense of sight, as well as a detection to vibration to locate their prey.

What do Northern Water Snakes eat?

These snakes are scavengers and carnivores by nature. This means that they eat a wide variety of prey, including fish, amphibians, crayfish, large insects, birds, turtles, leeches, small mammals, as well as other snakes. 

How do Northern Water Snakes avoid their predators?

These snakes usually escape their predators by swimming across the water, or by diving right below the surface. They usually anchor themselves to logs or vegetation. They usually stay submerged for around 5 minutes, though they can stay below water for up to an hour and a half. 

What is the role of Northern Water Snakes in the ecosystem?

These snakes help in controlling the populations of their main prey, including amphibians, fish, and other reptiles. 

Do Northern Water Snakes cause problems?

In general, these water snakes may cause a potential problem for fish farms and fish hatcheries. 

How do Northern Water Snakes interact with humans?

In contrast to popular belief, Northern Water snakes are beneficial towards fish populations. They usually feed on dying and diseased fish. They also help in controlling areas where there may be an overpopulation. This could turn out to be a positive thing for the sportfishing industry.

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