The 3 Venomous Snakes in Pennsylvania

There are three species of venomous snakes in Pennsylvania. The list includes the Eastern Copperhead, the Eastern Massasauga, and the Timber Rattlesnake.

These reptiles play a vital role in the environment by keeping rodent populations balanced. But they’re also dangerous to humans. In fact, in an average year around 64 people are bitten by venomous snakes in Pennsylvania.

Anyone venturing into the Keystone State’s outdoors should be educated on where these dangerous snakes live and what they look like. This guide will tell you those things. We’ll also tell you how to stay as safe as possible in Pennsylvania’s venomous snake country.

Pit Vipers: The Venomous Masters of Infrared Detection

Rattlesnakes, Copperheads, and Cottonmouths are among the most well-known members of the venomous Crotalinae subfamily, also referred to as pit vipers. These snakes are equipped with unique adaptations that make them exceptional hunters.

What Makes Pit Vipers Unique?

Infrared-Sensing Pits:
A defining feature of pit vipers is the deep facial pit between their nostril and the eye on each side of their head. These specialized infrared-detecting organs allow pit vipers to sense heat emitted by prey. This adaptation enables them to:
- Detect body heat from up to 1 meter away.
- Strike prey with pinpoint accuracy, even in complete darkness.
Triangular Heads and Vertical Pupils:
- Head Shape: Pit vipers are recognized by their distinct triangular-shaped heads, which house their venom glands.
- Eyes: They have vertical elliptical-shaped pupils.
Venomous Fangs:
Pit vipers have hollow fangs connected to venom glands. These fangs fold back against the roof of their mouth when not in use.

Ecological Importance

Pit vipers play a crucial role in maintaining ecosystem balance by controlling rodent populations. Despite their fearsome reputation, these snakes are vital to the health of many habitats.

Eastern Copperhead (Agkistrodon contortrix)

The Eastern Copperhead is a pit viper native to the eastern United States.

What Do Eastern Copperheads Look Like?

Size	*Adults range from 20 to 37 inches (50 to 95 cm) in length.
Coloration	Reddish-tan to grayish-tan bodies. Overlaid with dark brown, hourglass-shaped markings. *Heads are dark coppery brown, giving them the name “Copperhead.”
Body Shape	Stout and heavy-bodied snakes. As with all pitvipers, their heads are triangular and appear oversized in relation to their necks.
Conservation Status:	*Most common venomous snake in Pennsylvania.

Taxonomy of Pennsylvania’s Eastern Copperhead Snakes

Copperhead snakes are found across Pennsylvania and are now recognized as a single species: the Eastern Copperhead (Agkistrodon contortrix).

In the past, these snakes were classified into different subspecies, including the Northern Copperhead, Southern Copperhead, and Osage Copperhead. However, recent DNA studies revealed minimal genetic differences between them. As a result, these subspecies were combined into a single taxonomic group under the Eastern Copperhead name.

Where Do Eastern Copperheads Live in Pennsylvania?

Map of the Eastern Copperheads Range in Pennsylvania

You will find the Eastern Copperhead throughout Pennsylvania. They are found in rock piles, rocky woodlands, and river bottoms. The leaf and plant debris in these areas provide cover for them to hide in.

Eastern Copperhead Behavior

Copperheads are dangerous because they use camouflage as their number one defense mechanism. In other words, these snakes choose to lie perfectly still rather than flee most of the time. Their camouflage helps them blend in with leaf litter and other ground debris.

When they feel threatened, they occasionally mimic the tail vibration of a rattlesnake. But, in most cases, they choose to lie perfectly still.

Most copperhead bites on humans occur when the person steps on or near the snake.

What Do Copperheads Eat?

Copperhead snakes are opportunistic feeders. They eat large insects, spiders, small rodents, small animals, birds, and other reptiles.

How Dangerous Are Copperheads?

A Copperhead can bite and inject venom from the time they are newly born. Like most pit vipers, they have hemotoxic venom.

Most copperhead bites are not life-threatening. On the other hand, any bite from this snake is a medical emergency and should be treated as such. Prompt medical attention increases the chance of a good outcome.

Copperhead bites can cause severe pain, shock, and swelling. Their bites also have the potential to cause blood in urine, tissue damage, and kidney failure.

An interesting study has found that Copperhead venom contains a protein called contortrostatin. Contortrostatin has been found to stop the growth of cancer cells in mice.

Copperhead Hunting in Pennsylvania

It’s legal to take one Eastern Copperhead annually in Pennsylvania if you hold a venomous reptiles permit. A complete list of regulations is found here.

Rattlesnakes of Pennsylvania

Rattlesnakes are pit vipers. See the description of pit vipers above.

What Pennsylvania’s rattlesnakes have in common with most other rattlesnake species is their rattle.

Most rattlesnakes have a rattle at their tail’s end, comprised of hollow, loosely interlocked keratinous scales.
Normally, a rattlesnake adds a new segment to its rattle each time it sheds its skin.
An agitated rattlesnake rapidly vibrates its tail, causing the segments of its rattle to vibrate together, creating a buzzing or rattling sound.
Not all Alabama’s rattlesnakes rattle before they strike. Sometimes, they lose their rattles due to injury, and sometimes, they choose not to rattle.

Timber Rattlesnake (Crotalus horridus)

Timber Rattler and Canebrake Rattlesnake are both common names for the Timber Rattlesnake. Generally, in higher-elevation habitats, they are called Timber Rattlesnakes. On the coastal plain, though, they’re called Canebrake Rattlesnakes.

What Do Timber Rattlesnakes Look Like?

Size	Average length: 36 to 60 inches (0.91 to 1.52 m). Rare cases reported: Up to 7 feet (2.13 m).
Coloration	General base color: Yellowish-brown to grey-brown. Chevron pattern: Dark brown to black chevrons on their back and sides against a lighter base color. Back stripe: Rusty to reddish stripe running down their back. Tail color: Dark brown or black.
Melanistic Variation	Some timber rattlesnakes exhibit a dark, melanistic color morph. These snakes can appear almost entirely black. *The tail is darker than the rest of the body in this morph.
Behaviors	These snakes are excellent climbers. In fact, timber rattlers have been found in trees at heights of more than 80 feet. The experts have proven that timber rattlesnakes help control Lyme disease. This is because as they consume rodents, they’re also consuming ticks. A timber rattler will consume 2,500 to 4,500 ticks per year, depending on the location.
Conservation Status	Pennsylvania Fish and Boat Commission lists them as a threatened species.

Where Do Timber Rattlesnakes Live in Pennsylvania?

Map of the Timber Rattlesnake Range in Pennsylvania

Timber rattlesnakes are found throughout Pennsylvania.

They live in a variety of habitats. These include mountainous forests, pine forests, and farm fields. They can also be found in swampy areas and river floodplains. In the winter, they are found hibernating in crevices in the ground.

What Do Timber Rattlesnakes Eat?

Timber rattlers prey on small mammals such as mice, rats, squirrels, and chipmunks. They also eat small birds, other reptiles, and amphibians.

How Dangerous Are Timber Rattlesnakes?

Timber Rattlesnakes are among the most dangerous snakes in North America. This is due to their long fangs and high venom yield. 1% to 10% of untreated Timber Rattlesnake bites result in a fatality.

Fortunately, 40% to 60% of the time, they produce dry bites. In other words, although their fangs penetrate the body, they do not inject any venom.

These snakes produce hemotoxic venom. Timber Rattlesnake bites sometimes cause serious complications. These include shock, seizures, coma, internal bleeding, blood clots, and deep tissue damage. Source

Timber Rattlesnake Hunting in Pennsylvania

In Pennsylvania it’s legal to take one Timber Rattlesnake per year with a venomous snake permit. A harvested timber rattler must be at least 42 inches long and have 21 or more subcaudal scales. A full list of regulations is found here.

Eastern Massasauga Rattlesnakes (Sistrurus catenatus)

Massasaugas have a high-pitched rattle sound, which is different from other rattlesnakes. This is why they have the nickname Buzztail.

Size	*Adult Eastern Massasaugas average 22 to 30 inches (55 to 75cm) long.
Coloration	Their base color is light grey. Some melanistic snakes are almost entirely black in color.
Dorsal Spots	A row of large, rounded, blackish-brown spots run down their spine. They have three smaller rows of spots down each side. *In some cases, the larger dorsal spots connect with the side spots, forming a large solid blotch.
Head	*A dark stripe on each side of their face and across their eye.
Conservation Status	*Pennsylvania Fish and Boat Commission lists them as an endangered species.

Where Do Eastern Massasauga Rattlesnakes Live in Pennsylvania?

Eastern Massasaugas are on the Federal endangered list and are hard to find. However, they are most likely found in western Pennsylvania. They inhabit forested swamplands, marshy grasslands, lake edges, dry prairie, and woodlands.

Eastern Massasauga Rattlesnake Behavior

The Eastern Massasauga is generally thought to be docile and slow to be provoked.

They also have a reputation for being shy, timid snakes. They prefer to lie motionless in tall grass or leaf litter and let you pass by. If you approach too closely, they’ll attempt to escape to deeper cover if they’re not cornered.

This doesn’t mean they won’t bite you, though. The NIH cataloged 848 Massasauga bites in the Great Lakes region between 1800 and 2015.

The rattle of a massasauga is different from other rattlesnakes. It’s high-pitched and sounds more like the buzzing of a bee than a snake’s rattle.

If you come upon an eastern Massasauga too suddenly, it may bite you without rattling.

What Do Eastern Massasauga Rattlesnakes Eat?

An Eastern Massasauga’s primary prey is small mammals such as mice and voles. They also eat frogs, toads, and small snakes.

How Dangerous Are Eastern Massasauga Rattlesnakes?

Eastern Massasaugas are generally docile and slow-moving unless they are provoked.

The venom of the Massasauga rattlesnake is cytotoxic. Cytotoxic venom destroys body tissue. Moreover, digestive enzymes in cytotoxic venom disrupt blood flow and prevent clotting. Massasauga bites to humans are rare. However, they do occur and are potentially fatal.

There are two documented deaths in Ontario from Eastern Massasauga rattlesnake bites. In each case, the victim did not receive antivenom in time.

Pennsylvania’s Venomous Snakes in Winter: Insights into Brumation

During winter, Pennsylvania’s snakes, like all reptiles, enter a dormant state called brumation—a hibernation-like period. Because snakes are ectothermic (cold-blooded) and cannot regulate their body temperature internally, they slow their metabolism and become inactive during the colder months.

Brumation Habits

Solo vs. Communal Brumation: Some snakes brumate alone, while others gather in communal dens. For example, Eastern Copperheads and Timber Rattlesnakes often share dens, which may house up to 60 snakes.
Mixed-Species Dens: Interestingly, these dens can include non-venomous species. It’s not uncommon to find Black Rat Snakes or Eastern Black Racers sheltering alongside venomous snakes.

Regional Variations

Snakes may only seek shelter in warmer areas on the coldest winter days. They might not enter full brumation due to milder conditions.

Where Snakes Spend Winter

Snakes seek out protected spots to brumate, such as:

Rock crevices
Hollow logs
Fissures on rocky hillsides

They often choose south-facing slopes because these areas receive more sunlight, providing additional warmth during winter.

This natural adaptation allows Pennsylvania’s venomous snakes to survive the winter and re-emerge when temperatures rise.

Avoiding Snake Bite

Copperheads are Pennsylvania’s most common venomous snake. These snakes rely on their excellent camouflage to stay hidden. They often remain perfectly still to avoid detection. If you’re walking in the woods and unknowingly get too close, a copperhead might not move, hoping you’ll pass by. Many bites happen when someone accidentally steps on the snake. To stay safe in snake habitats, always watch where you step and where you place your hands.

Another common cause of snake bite is attempts to capture or kill a snake. Remember, venomous snakes can strike instantly, delivering a potentially life-threatening bite. The safest approach is to keep a safe distance and leave them alone.

Dressing for Snake Country

High-top leather boots and long pants are both wise ideas.
Also, wear loose-fitting denim. If there’s a gap before the snake’s fangs touch your skin, your chances of being envenomated are lower.
In the absence of high-top leather boots, some people wear snake gaiters.

Symptoms of Venomous Snake Bites

Some of the symptoms you may experience when a venomous snake bites you include:

Discoloration in the area of the bite.
Swelling in the area of the bite.
Loss of muscle coordination.
Tingling sensation in the area of the bite.
Feeling nauseous.
Having a faster heartbeat or rapid pulse.

What Should You Do if You Are Bitten?

If you or someone you are with has suffered a venomous snakebite, time is of the essence. Because the sooner a victim receives antivenom, the less chance the venom in their body has to cause harm. In other words, it is important to seek immediate medical attention.

Do not attempt to kill the snake for identification purposes. This gives the snake a chance to bite you again. Also, consider that severed snakeheads can still bite and envenomate and often do. If you have a phone, take a picture of the offending reptile. Otherwise, get started on your way to the nearest hospital.

First Aid for Snake Bite Victims

Remain calm and limit your movements. Do not run. If you must hike back to a vehicle, do it calmly and deliberately. Put as little stress on your heart as possible.
Keep the area of the snake bite below the heart level and never above the heart level. Keeping the bite below the heart level will reduce the venom’s flow. However, holding the bite above your heart level will increase the venom’s flow.

Remove all constricting items such as bracelets, watches, or rings before swelling occurs.
Remember that using a cold compress on a venomous snake bite is not advisable. The cold may cause the local blood vessels to constrict and spread the venom faster.
You can wash the affected area like any other wound with soap and water.
You may cover the bite area with a moist dressing to reduce the swelling.

Get help as soon as possible. Call the hospital to tell them a venomous snake has bitten you. So they can have antivenom ready to give you when you arrive.
A person whom a venomous snake has bitten may go into shock. If this happens, lay them flat and cover them with a blanket.

Conclusion

Pennsylvania’s venomous snakes, including the Eastern Copperhead, Timber Rattlesnake, and Eastern Massasauga, are fascinating and yet, potentially dangerous creatures. They play a crucial ecological role by controlling rodent populations and maintaining balance in their habitats. However, their presence requires vigilance, especially for outdoor enthusiasts.

To minimize risks, educate yourself about these snakes’ habitats, appearance, and behaviors. Wear appropriate protective clothing, stay alert in snake-prone areas, and avoid handling or provoking these reptiles. In case of a snakebite, seek medical attention immediately and follow first-aid guidelines to ensure the best outcome.

Understanding and respecting these reptiles allows us to coexist safely while appreciating their importance in nature. Stay informed, take precautions, and enjoy Pennsylvania’s outdoors responsibly.