There are 21 different species of snakes in the state of Pennsylvania. Out of these, there are 3 venomous snakes. This article will first list the species of venomous snakes. Then, we’ll describe each snake and tell you where you will likely find them in the Keystone State.
- Eastern Copperhead (Agkistrodon contortrix)
- Timber Rattlesnake (Crotalus horridus)
- Eastern Massasauga (Sistrurus catenatus catenatus)
Pit Vipers
Rattlesnakes, Copperheads, and Cottonmouths belong to the venomous Crotalinae or pit viper family. Another name for these snakes is pit vipers. Pit vipers have heat-sensing pits between their nostrils and eyes. These pits are actually specialized organs that detect infrared radiation from prey animals. Pit organs enable pit vipers to strike their prey precisely, even in the dark. They are also able to detect body heat from about 1 meter away.
Pit vipers have hollow fangs connected to venom glands. They use their fangs to inject venom into their prey. This venom immobilizes their small prey, making it easier for the snake to consume. They primarily consume small mammals, reptiles, amphibians, and small birds. These snakes play vital roles in maintaining balance in rodent populations.
Eastern Copperhead
| Scientific Name: | Agkistrodon contortrix |
| Description: | Adult copperheads are 20 to 37 inches (50 to 95 cm) long. Their bodies are coppery brown overlayed with dark brown hourglass blotches. |
| Habitat: | Deciduous forests, river bottoms, and rocky wooded hillsides. |
| Conservation Status: | Most common venomous snake in Pennsylvania. |
Eastern Copperheads are pit vipers native to the eastern United States. Pennsylvania was formerly home to the Northern Copperhead subspecies. However, DNA analysis shows little genetic difference between the two. Today, the former Northern Copperheads, Southern Copperheads, and Osage Copperheads are taxonomically combined. The common name for these snakes is Eastern Copperheads. Their scientific name is Agkistrodon contortrix. Source
Copperheads are stout heavy-bodied snakes. Adult copperheads are 20 to 37 inches (50 to 95 cm) long.
Eastern Copperhead snakes have reddish-tan to grayish-tan bodies. Their bodies are overlaid with hourglass-shaped dark brown markings. Their triangular head is proportionately large. The color of their head is dark coppery brown. This is the reason they have the name “Copperhead.”
Where Do Eastern Copperheads Live 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.
Wintertime Brumation
Snakes do not tolerate the cold weather in the winter months very well. They are ectotherms, which means they can not regulate their body temperature internally. Physiologically, ectotherms cannot hibernate. Yet, they go into a state of suspended animation called brumation for up to 6 months out of the year.
Copperheads winter underneath rocks, in hollow logs, and in fissures on rocky hillsides. An individual might brumate alone in some parts of their range. But copperheads tend to be social. In some areas, they congregate together in dens with other snakes through the winter.
In hilly terrain, south-facing slopes capture more radiant warmth from the sun. So, that is where these dens are generally located. The other snakes they den with are not necessarily just copperheads. Sometimes, they share their dens with other species of snakes. You may find a Timber Rattler or a Black Rat Snake sharing the same den with copperheads. These wintertime dens may hold up to 60 snakes.
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.
Timber Rattlesnake
| Scientific Name: | Crotalus horridus |
| Description: | Adult Timber Rattlesnakes grow between 36 and 60 inches (.91 to 1.52m) long. Their bodies are yellowish-brown with a dark chevron pattern. They also have a rusty stripe down their backs. Their tails are dark brown or black. |
| Habitat: | Timber Rattlesnakes prefer wooded areas and hillsides with rocky outcrops. |
| Conservation Status: | Pennsylvania Fish and Boat Commission lists them as a threatened species. |
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.
The average Timber Rattlesnake grows between 36 to 60 inches (.91 to 1.52m) long. However, there have been reports of them growing up to 7 feet (2.13m) long. See
These snakes vary in color. Their general base coloration is a yellowish-brown to grey-brown, though. They have a dark brown to black chevron pattern on their back and sides against a lighter base color. Moreover, they have a rusty to reddish stripe down their backs. Their tails are dark brown or black with a tan rattle. There are also melanistic timber rattlers. These are dark and sometimes almost entirely black. In the dark color morph of these snakes, the tail is also darker than the rest of the snake’s body.
Where Do Timber Rattlesnakes Live 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. These snakes are marvelous climbers and have been found in trees at heights of more than 80 feet. Source
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.
These snakes are excellent climbers. In fact, timber rattlers have been found in trees at heights of more than 80 feet. Source
In 2013, University of Maryland researchers conducted a study. This study has 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. See
Wintertime Brumation
As we discussed in the section on copperheads, snakes brumate in the winter. Brumation is a reptile’s version of hibernation.
Timber Rattlesnakes make wintertime dens in sheltered spots. They den underneath rocks and logs, as well as in fissures in rocky hillsides. An individual Timber Rattler might brumate alone in some parts of their range. But in other areas, they congregate in dens with other snakes through the winter.
Dens are usually placed on slopes facing south because they get more warmth from the sun. They don’t always share their dens only with Timber Rattlers. Sometimes, they share their dens with other species of snakes. These might include Copperhead, eastern rat snake, and northern black racer. These wintertime dens may hold up to 60 snakes. Source
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. Source
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
Eastern Massasauga
| Scientific Name: | Sistrurus catenatus |
| Description: | Adult Eastern Massasaugas average 22 to 30 inches (55 to 75cm) long. Their body is light grey with dark brown blotches. |
| Habitat: | Wet habitats such as swamps or marshy areas near lakes or streams. |
| Conservation Status: | Pennsylvania Fish and Boat Commission lists them as an endangered species. |
Eastern Massasaugas are sometimes called swamp rattlers. They are one of two rattlesnake species native to the Great Lakes states. The other is the Timber Rattlesnake.
An adult Massasauga rattlesnake grows to a length between 22 to 30 inches (55 to 75cm). Some individuals may exceed this length.
Their body is a light gray with dark blotches along the spine and along the sides. They also have a dark stripe on each side of their face and across their eye and a white stripe on their heads. Some melanistic snakes are almost entirely black in color.
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. Source
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. Source
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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.
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.
