Venomous Snakes in Pennsylvania: 3 Species & How to Tell

Sources

1. Pennsylvania Native Reptile and Amphibian Species (PA Species and Endangered Species Act listing status). Pennsylvania Fish and Boat Commission. undated page; checked November 3, 2026.
   Quoted passages (1)

   “Pennsylvania is home to a diverse population of amphibians and reptiles, including 22 species of salamanders, 21 snakes, 18 frogs and toads, 13 turtles and four lizards.”

2. Reptiles and Amphibians FAQs. Pennsylvania Fish and Boat Commission. undated page; checked November 3, 2026.
   Quoted passages (2)

   “There are only three venomous snakes native to PA: the Eastern Copperhead, Timber Rattlesnake and Eastern Massasauga.”

   “Water Moccasins or Cottonmouths are not native to PA. They are found primarily in the southern states. Their range only goes as far north as southern Virginia.”

3. Snakes (species accounts). Pennsylvania Fish and Boat Commission. undated page; checked November 3, 2026.
   Quoted passages (14)

   “Although usually quick to flee, the black racer can become a fierce fighter when cornered or somehow made to feel trapped. Left to itself, it is harmless.”

   “This relatively small snake is harmless, although it can emit a pungent, unpleasant-smelling musk that may help repel an attacker.”

   “Then, inflating the body with air, hissing and striking out, the hog-nosed snake suddenly resembles a fearsome-looking creature, but it is harmless.”

   “Often killed by people out of fear, the northern watersnake is not a water moccasin and it is not venomous.”

   “One of only three venomous snakes common to Pennsylvania, the eastern copperhead is a close cousin of the cottonmouth or water moccasin found in more southerly aquatic environments.”

   “If the strike hits its intended victim, poison may be injected through two hollow fangs connected to glands located on each side and toward the rear of the head. … The venom is a hemotoxin, but with a trace of neurotoxin and as such primarily affects the bloodstream.”

   “Though not the largest snake found in Pennsylvania, the timber rattlesnake has the distinction of being the largest of our three venomous species.”

   “Contrary to popular belief, the timber rattlesnake does not always sound its familiar alarm before striking. In fact, when striking because of fear or the need to defend itself, more often than not the snake strikes without an audible warning.”

   “The eastern massasauga is a rattlesnake. It is the smallest of Pennsylvania's three venomous snakes, but the one with the biggest problem.”

   “Nine plates (actually large scales) cover the crown of the head, compared to the timber rattlesnake's numerous small scales.”

   “Contrary to popular belief, the timber rattlesnake does not always sound its familiar alarm before striking.”

   “Able to tolerate colder temperatures, it leaves the den first in the spring and it's the last to hibernate in the fall.”

   “The eastern massasauga is a rattlesnake.”

   “Thus, the dark pattern on the milksnake is at its widest across the midline of the back, compared to the narrower dark band on the midline of the copperhead.”

4. Timber Rattlesnake Conservation. Pennsylvania Fish and Boat Commission. undated page; checked November 3, 2026.
   Quoted passages (2)

   “If you see a snake, of any species, do not kill or attempt to move or capture it. Instead, retreat calmly and allow the animal to continue its course or seek cover.”

   “PFBC Waterways Conservation Officers are trained to handle venomous snakes. Call a local officer to have them safely capture the snake and relocate it to a suitable area nearby.”

5. Pittsburgh Poison Center at UPMC Offers Tips to Stay Safe Around Venomous Snakes During Summer. Pittsburgh Poison Center at UPMC. May 27, 2016; checked November 3, 2026.
   Quoted passages (1)

   “If the patient loses consciousness, has chest pain, trouble breathing or a sense of throat/tongue swelling, CALL 911 IMMEDIATELY. … Otherwise, call the regional poison center at 800-222-1222.”

6. Pennsylvania Amphibians & Reptiles (Larry L. Shaffer; reference book). Pennsylvania Fish and Boat Commission. ©1999; checked November 3, 2026.
   Quoted passages (1)

   “The copperhead, like so many other reptiles and amphibians, enjoys a day in the sun and often basks on a favorite rock, especially on a warm day in the spring or fall. During the hotter days of summer, the copperhead seeks relief from the piercing rays of the sun and becomes more nocturnal in its habits.”

7. Feral Swine. Pennsylvania Game Commission. undated page; checked November 3, 2026.
   Quoted passages (1)

   “Any observations of feral swine in the commonwealth should immediately be reported to the Game Commission at 1-833-PGC-WILD or 1-833-PGC-HUNT.”

8. GBIF.org occurrence records, human observations licensed CC0 1.0 or CC BY 4.0 only, accessed November 3, 2026. The datasets behind these counts are listed on our Sources page.