Water moccasins, also known as cottonmouths, are a common subject of concern, with many wondering if these venomous snakes inhabit their local areas. In Indiana, understanding their actual distribution and how to differentiate them from other aquatic snakes is important for safety and appreciating local wildlife. This clarifies common misconceptions and guides safe interactions with snakes.
Are Water Moccasins in Indiana?
Water moccasins, or cottonmouths (Agistrodon piscivorus), are listed as a state endangered species in Indiana. Confirmed populations are extremely rare and localized, known to exist in only one small area in southwestern Indiana’s Dubois County. However, there’s strong indication these snakes may no longer occur in Indiana, with no confirmed sightings in over ten years.
Despite their limited or absent presence, the common watersnake (Nerodia sipedon) is frequently mistaken for the cottonmouth across Indiana. This misidentification leads to many harmless Northern Watersnakes being unnecessarily killed each year due to fear. The widespread distribution of non-venomous water snakes contributes to the belief that water moccasins are common statewide.
Identifying Water Moccasins
Distinguishing a water moccasin from other snakes involves observing key physical characteristics and behaviors. They possess a large, blocky, triangular head noticeably wider than their neck, due to venom glands. Their eyes feature elliptical, cat-like pupils, and they have heat-sensing pits between their eyes and nostrils.
The body is stout, thick, and heavy, often ending in a short, thick tail. While adults are uniformly dark (brown to black), juveniles display distinct dark-brown bands on a lighter background and a bright yellow-green tail tip. When threatened, a water moccasin may coil and expose the white, cotton-like lining of its mouth, a defensive display giving it its common name. These snakes also tend to be buoyant, swimming with their entire body on top of the water, and often hold their ground rather than fleeing.
Common Indiana Water Snakes
Many non-venomous water snakes are common throughout Indiana and frequently mistaken for water moccasins. The Northern Water Snake (Nerodia sipedon) is the most prevalent aquatic snake statewide, often leading to misidentification. These snakes play an important role in aquatic ecosystems.
Unlike water moccasins, Northern Water Snakes have more slender bodies and longer, thinner tails. Their heads are narrower, not distinctly wider than their necks, and they have round pupils. While they may flatten their heads when threatened, their head shape remains less blocky than a cottonmouth’s. Northern Water Snakes typically flee quickly when disturbed and swim with only their head visible above the water surface. Other Indiana water snakes confused with moccasins include the Midland Water Snake and the Copperbelly Water Snake.
Safe Encounters with Snakes
Encountering any snake in the wild requires a cautious approach for safety. Always give snakes ample space and observe them from a distance. Avoid attempting to handle or provoke a snake, as most bites occur when individuals try to interact with or harm the animal.
When outdoors, wear appropriate footwear, such as closed-toe shoes and long pants, especially where snakes might be present. Avoid placing hands or feet into areas with limited visibility, like under logs or rocks. If a snake is found near a home or building, contact local animal control or a professional snake removal service, rather than attempting removal yourself. In the rare event of a snake bite, seek immediate medical attention.