Black Swamp Snake (Liodytes pygaea) Info & Pictures

The black swamp snake is a small, harmless non-venomous snake that is native to the eastern United States of America.

This species prefers to live in wet areas with a high density of vegetation, which is why it is found primarily in swamps, lakes and marshes.

Physical Description

This snake is a black color made to blend in with its surroundings, and a bright red belly. The word pygaea is derived from the Greek meaning “fire-like,” probably referring to their color.

They have smooth scales, with soft bristles covering their head and neck; however, these can become lost over time due to normal wear on their bodies.

The black swamp snake is a secretive creature not often seen by humans. They are seen both during the day and night and shy and are usually found under logs and bridges, by the edges of swamps and lakes, or in fields and backyards at night.

It will not bite unless provoked.

Habitat and Distribution

black swamp snake head
Photo: tom spinker

This snake is native to the coastal areas of southeastern Canada and the eastern United States (also known as the Southeast).

This species is found in most United States, including the Atlantic Coast, central-eastern U.S., southern Illinois, southern Indiana, Michigan, northern Missouri, Georgia (except for parts of extreme north), north Mississippi, and Alabama as Puerto Rico.

Despite its name, “black swamp snake,” it prefers habitats with a higher vegetation density (such as cypress trees).

The black swamp snake can be found in wetland areas, marshes, swamps, cypress swamps, ponds, ditches, and streams.

The active season for this subspecies occurs from March through August. In some areas, they can be found on farms that use pesticides and fertilizers in their vegetation. They can also be found in wooded areas, residential areas, and parks.


Black swamp snakes are nocturnal; although adults of this species will often be out during the day, it is rare. These snakes are also shy and will not bite unless handled or cornered. When threatened, they will coil their bodies to appear larger than they are – however, these coils constrict their ability to breathe and cause them to suffocate. They have been known to have a rough time digesting food since their habitat is slow-moving water with a lot of vegetation; thus, they have been known to eat non-nutritive items such as rocks and gravel.

One of the most exciting characteristics of this species is called catfishing; when they sense vibrations in the water below them, they strike from an underwater position to capture their prey. Upon capture, they will let go and submerge back into the water.

Diet and Hunting Techniques

These snakes feed mainly on frogs, mostly at night during the moon phase.

They are highly secretive animals that hunt in the undergrowth by waiting for prey to come near before striking out with their fangs and rapidly moving to catch the prey before being discovered by predators.

Diet is highly varied, with species such as the northern leopard frog and the leopard frog prey. This particular snake has a chance of biting if it is stepped on.

Because their habitat is usually covered in vegetation, stepping on this snake could cause it to be forced to bite in self-defense. This is not a natural behavior for these snakes and should never be attempted with this species.

When provoked, the black swamp snake will also use its tail as a weapon against predators by whipping it at them and releasing feces from its cloaca.

Predators and Red Tape

White Ibis in flight with a Black Swamp Snake
White Ibis in flight with a Black Swamp Snake

This snake is tiny in size and cannot harm humans. However, its small size is often preyed upon by raptors, other snakes, and weasels.

The black swamp snake does not face any special protection measures under the Endangered Species Act in the United States or Canada. Population monitoring and conservation are typically handled by the state of interest or private organizations.

Interaction with Humans 

This snake is typically harmless to humans; however, direct handling should be avoided, as a bite from this species can cause mild reactions ranging from swelling and itching to nausea and dizziness.

Diet & Feeding Habits

The black swamp snake is an omnivore; their diet consists of small fish, tadpoles, frogs, salamanders, sirens, amphiumas, leeches and earthworms. however, it is likely not to consume other snakes.

These snakes do not have venom glands in their mouth, so they will not use their bite to kill prey; instead, they will wrap the prey with their body or use an open jaw.

The black swamp snake’s diet consists primarily of amphibians and other reptiles, and small arthropods, which they hunt in dense aquatic vegetation.

This snake is a sit and waits for a predator, meaning it will position itself in a place where they see its prey regularly traveling.

As their prey passes by, they will grab the animal with their mouth and hold on until the prey stops struggling. The black swamp snake will then swallow the animal whole.


These aquatic snakes are an ovoviviparous species, meaning they give birth to live young that develop inside the female’s body. Unlike other snakes, the black swamp snake does not give birth to eggs.

After mating, a female will retain the eggs for about three weeks, after which time she will release approximately 20-30 live young. When born, the baby snakes are about 2 inches (5 centimeters) in length.

The black swamp snake undergoes one breeding season, alternating between the spring and summer seasons, according to this study this is when the temperatures are most appropriate for reproduction.

The snakes will engage in choruses, a series of calls from the male to attract a female. These choruses can consist of short blasts to long, continuous trills.

The males will attract the females mainly through their calls. Once a male has attracted a female, he will follow her until she is ready to mate.

The male will then align himself behind the female and position his cloaca to meet hers. He will then transfer sperm to her cloaca for fertilization.

Conservation Status and Threats

The black swamp snake has a conservation status of “Least Concern” because its population is relatively large, stable, and healthy enough to make up for human-caused deaths by habitat loss (from the expansion of towns).

The main threat to this species is habitat loss due to drainage caused by land-use changes or expanding towns.

There is also a possibility that this species will become more of a problem than it already is because they are large enough to prey on humans.

The black swamp snake is protected from accidental capture by private individuals, and it does not have any listed trade names.

It was also placed on the U.S. Fish and Wildlife Service IUCN Red List in 2001 as “Data Deficient.” According to the Southeastern Environmental Defense Center, this species has been identified as being caught in the wild for medicine.


The black swamp snake is from a subfamily of colubrids called Natricinae, a group of snakes that all share a venom gland in their jaws called the fangs. The subfamily is a minority of the colubrid family.

The black swamp snake is the only black swamp species and the only “Liodytes.” All of them are from a subfamily of colubrids called Natricinae, snakes with fangs (for venom delivery) in their jaws.

The broad-banded water snake is usually considered a synonym of Liodytes pygaea, but it is sometimes placed in a genus for scientific classification purposes.

The black swamp snake can be confused with the green water snake (Nerodia erythrogaster), a poisonous species of non-venomous snake that shares the same habitat with this harmless species (black swamp).

The poisonous species also has greenish-brown or grayish-green skin rather than the darker reddish-brown color that this harmless species has. The tail of the green water snake is also slightly shorter than the black swamp snake.

There are three currently recognized subspecies:

  • South Florida swamp snake, Liodytes pygaea cyclas (Dowling, 1950)
  • Carolina swamp snake, Liodytes pygaea paludis (Dowling, 1950)
  • North Florida swamp snake, Liodytes pygaea pygaea (Cope, 1871)

Frequently Asked Questions

Interesting Facts about Black Swamp Snakes

Black swamp snakes are not venomous, but they can bite.

The black swamp snake is not venomous and will only use its bite if they feel threatened or have to defend itself from predators.

If a black swamp snake bites you, you should clean the area with soap and water to prevent infection, then seek immediate medical attention at a local hospital.

The black swamp snakes’ camouflage coloration reduces their chance of being attacked by predators.

The black swamp snake’s colors help them blend in with their environment and decrease the risk of being attacked by predators like other species of snakes and birds.

Black swamp snakes are good swimmers.

The black swamp snake tends to swim in its natural habitat because it can easily move between underwater surfaces, unlike other species of snakes with limited swimming capabilities.

The black swamp snake is not aggressive when threatened by humans.

Although the black swamp snake can threaten humans if given a chance and the right situation, it is not known for being virulent or aggressive.

Black swamp snakes are active during day and night.

The activity patterns of this species vary from season to season, but they are consistently active during all times of day and night in all seasons


Winne, C.T., Dorcas, M.E. and Poppy, S.M., 2005. Population structure, body size, and seasonal activity of Black Swamp Snakes (Seminatrix pygaea). Southeastern Naturalist4(1), pp.1-14.

Sever, D.M., Stevens, R.A., Ryan, T.J. and Hamlett, W.C., 2002. Ultrastructure of the reproductive system of the black swamp snake (Seminatrix pygaea). III. Sexual segment of the male kidney. Journal of morphology252(3), pp.238-254.

Dowling, H.G., 1950. Studies of the black swamp snake, Seminatrix pygaea (Cope), with descriptions of two new subspecies.

Willson, J.D. and Winne, C.T., 2016. Evaluating the functional importance of secretive species: a case study of aquatic snake predators in isolated wetlands. Journal of Zoology298(4), pp.266-273.

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