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Are There Water Snakes in Rhode Island?

Rhode Island is known for its stunning beaches, iconic lighthouses, and delicious seafood. But there’s another side to this small New England state that few people know about. Beneath the surface of its rivers and streams, Rhode Island is home to a variety of wildlife.

From fish to frogs and turtles to salamanders, there’s always something swimming in the state’s waters. But perhaps most intriguing are the water snakes that call this place home. Read on to learn more about these reptiles.

The water snake species in Rhode Island

A snake must belong to the genus Nerodia to be considered a true water snake, and out of the nine species of Nerodia snakes, only one is found in Rhode Island: the Northern Water Snake.

The northern water snake

Northern water snake on log
Northern water snake on log | image by Peter Paplanus via Flickr | CC BY 2.0
  • Scientific name: Nerodia sipedon sipedon
  • Range: Commonly found in the lowland marshes and areas near the ocean of southeastern Rhode Island, as well as the rivers and lakes of northern Rhode Island.


The Northern water snake is a heavy-bodied grayish-brown snake with dark brown, reddish-brown, or black blotches along its back. It has two rows of square spots that run down each side of its body.

Its ventral side is usually yellowish in color, with one to four rows of black half-moon-shaped markings. Juveniles of this species are more brightly colored than adults, with brownish-gray blotches along their backs and a yellow belly.

It has a flat head and round pupils, and its lips are usually white or yellowish with distinct, vertical black markings on them. Additionally, it has a divided anal plate, meaning it has two separate scales at the base of its tail. Its scales have a keeled appearance, meaning they have tiny raised ridges along the centerline of each scale.

Adult northern water snakes typically measure between 24 and 42 inches in length, though some can grow up to 55 inches; females are usually larger than males. Unfortunately, due to its appearance, the northern water snake is often mistaken for the venomous cottonmouth (Agkistrodon piscivorus), also known as a water moccasin which is not a true water snake but rather a semi-aquatic viper.

Water Moccasin
Water Moccasin/Cottonmouth | U.S. Fish & Wildlife Service Southwest Region

To differentiate between the two, look for differences in body shape and behavior. The northern water snake has a flat head and a divided anal plate, while the cottonmouth has a triangular-shaped head and an undivided anal plate. Additionally, the northern water snake is typically less aggressive than the cottonmouth and will often attempt to flee when disturbed.

Behavior and diet

Northern water snake at rest
Northern water snake at rest | image by Peter Paplanus via Flickr | CC BY 2.0

Northern water snakes are extremely capable swimmers and can move rapidly both above and below the surface of the water. They are often found near the edges of rivers, lakes, ponds, and streams, either hunting for prey or basking in the sun on logs, rocks, or vegetation. They prefer shallow water with aquatic vegetation, logs, and rocks.

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These snakes are active during the day and spend most of their time foraging for prey, such as fish, frogs, tadpoles, and salamanders. They are often seen hunting near the surface of the water, waiting for their prey to come close. They will strike quickly and swallow their prey whole, usually head-first.

Northern water snakes are solitary creatures for most of the year but become social in the fall and spring when they gather in groups at basking sites. During the warmer months, it is quite common to spot them sunning themselves on overhanging branches, beaver lodges, and dried cattail stems.


Every spring, Northern water snakes come together to mate from April through June. After a gestation period of roughly 58-60 days, the female will give birth to a litter of 20-50 live young between early August and late September.

The young are typically 6-9 inches in length and are immediately independent, starting to hunt for food on their own shortly after birth. They reach sexual maturity at three years of age.

Here are some frequently asked questions about water snakes in Rhode Island

Is the northern water snake venomous?

No, the northern water snake is not venomous. However, its saliva does contain anticoagulants that affect the blood’s ability to clot, so it’s best not to handle them as they may defend themselves by biting. Due to their similar appearances, it is often mistaken for the venomous cottonmouth, also known as a water moccasin.

Are there semi-aquatic snakes in Rhode Island?

Rhode Island has two semi-aquatic snakes: the eastern ribbon snake (Thamnophis sauritis sauritis) and the northern red-bellied snake (Storeria occipitomaculata occipitomaculata).

Eastern ribbon snake

The eastern ribbon snakes are non-venomous colubrid snakes. They are slender, with small heads and an average length of 18 to 26 inches. The body is dark green, brown, or blacklight in color, with three yellowish stripes running down its back.

The ventral side is yellow or white in color. Eastern Ribbon snakes typically inhabit wetlands or slow-moving streams but can also be found near grassy areas and forest edges. They feed on frogs, salamanders, small fish, and other aquatic animals.

Northern red-bellied snake

The Northern Red-bellied Snake is a small, nonvenomous colubrid snake found in rural western Rhode Island. They typically grow between 8 to 10 inches long with a maximum length of 16 inches. Their back is usually brown, gray, or orange in color, and they often have three cream-colored dots on their neck.

The snake’s underside is bright red or orange, and its scales are keeled, giving them a rough texture. These snakes inhabit damp woodlands or near streams, where they feed on slugs, worms, and other invertebrates.

Are water snakes endangered?

No, water snakes are not considered endangered in Rhode Island. The northern water snake is, however, listed as a species of special concern due to its declining population.

Their population has been affected by habitat destruction, pollution, and humans killing them out of fear or misunderstanding. It is important to remember that these snakes play an important role in the ecosystem, helping to keep their environments healthy by controlling prey populations.

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Can you keep a northern water snake as a pet?

No, it is illegal to keep a northern water snake as a pet in Rhode Island. It is also illegal to keep any other native snakes from Rhode Island, such as the eastern ribbon snake, the red-bellied snake, and the common garter snake, among others. These snakes are protected by law and should not be removed from their natural habitats.

You can go a step further and say that it is actually against federal law to remove any animal from its natural habitat in order to keep it as a pet. So don’t keep wild-caught snakes, or any other animals, as pets if you’re in Rhode Island or any other state in the U.S.