Many people wonder about the presence of cottonmouths in Pennsylvania. This article clarifies their distribution and distinguishes them from other native species.
The Definitive Answer
Cottonmouths (Agkistrodon piscivorus) are not native to Pennsylvania. Despite occasional reports, scientific evidence confirms these venomous snakes do not occur within the state’s borders. Their absence is widely accepted by wildlife experts.
Common Look-Alikes in Pennsylvania
Misidentification often leads to the belief that cottonmouths inhabit Pennsylvania. The Northern Water Snake (Nerodia sipedon) is frequently mistaken for a cottonmouth due to its aquatic habits and defensive behaviors. This non-venomous snake can be found in various aquatic environments across Pennsylvania and may flatten its head when threatened, making it appear more formidable.
Pennsylvania is home to three native venomous snake species: the Eastern Copperhead (Agkistrodon contortrix), the Timber Rattlesnake (Crotalus horridus), and the Eastern Massasauga Rattlesnake (Sistrurus catenatus). Copperheads possess an hourglass-shaped banding pattern and a distinctive copper-colored head. Timber rattlesnakes are recognized by their large, triangular heads, stout bodies, and the rattle at the end of their tail. All venomous pit vipers in Pennsylvania, including copperheads and rattlesnakes, have elliptical pupils and heat-sensing pits between their eyes and nostrils.
Where Cottonmouths Actually Live
Cottonmouths are primarily found across the southeastern United States. Their natural range extends from southern Virginia, west through central Texas, and north to southern Illinois and Missouri. These semi-aquatic pit vipers prefer habitats near water, such as swamps, marshes, slow-moving streams, and lakes. They are also found in brackish-water habitats and can swim between barrier islands and the mainland.
Coexisting with Pennsylvania’s Native Snakes
Encountering any snake in Pennsylvania, whether venomous or non-venomous, calls for respectful caution. It is important to observe snakes from a safe distance and never attempt to handle, harass, or harm them. Snakes play an important role in the ecosystem by helping to control rodent and insect populations.
If a snake is encountered in an unexpected location, such as a basement or garage, it is best to leave it alone and allow it to move away on its own. For situations where a snake might pose a perceived threat or requires removal, contacting local wildlife authorities or a professional snake handler is advisable. Understanding and respecting Pennsylvania’s native snake species promotes safe coexistence in shared environments.