Snakes often evoke curiosity and apprehension, particularly when encountered in their natural environments. Some species inhabit lake environments, adapting to life in and around fresh water. While many are harmless, some are venomous, making identification and safe behavior important for those near these habitats.
Water-Dwelling Snakes and Their Habitats
Many snake species thrive in aquatic environments, including lakes, rivers, and swamps, adapting to these habitats through specialized behaviors and physical traits. In North America, water snakes of the genus Nerodia are common in freshwater bodies. The Northern water snake (Nerodia sipedon), for example, is widespread across the eastern United States and parts of Canada, often reaching lengths of 1 to 1.4 meters (3 to 4.5 feet). These non-venomous snakes have stout bodies with keeled scales, aiding navigation in watery surroundings. Their diet primarily consists of fish and amphibians, hunted in shallow waters or among aquatic vegetation. They are often seen basking on rocks, logs, or branches near the water’s edge to regulate body temperature.
In the southeastern United States, the venomous cottonmouth (Agkistrodon piscivorus), also known as the water moccasin, is a highly aquatic pit viper found in swamps, marshes, rivers, and ponds. Cottonmouths are ambush predators, waiting for prey such as fish, amphibians, reptiles, birds, and small mammals. Adults typically display dark bodies with crossbands, while juveniles often have brighter patterns and a yellow tail tip used as a lure. Unlike many non-venomous water snakes, cottonmouths tend to swim with their entire body afloat on the water’s surface due to their heavier build.
Identifying Lake Snakes and Staying Safe
Distinguishing between non-venomous water snakes and venomous species like the cottonmouth is important for safety, though maintaining distance from any snake is always recommended. A key characteristic is head shape: water snakes generally have more slender heads that flow smoothly into their bodies. Cottonmouths possess a broader, more triangular head distinct from their neck, often due to their venom glands. However, some non-venomous snakes can flatten their heads to appear larger when threatened, making head shape alone an unreliable indicator.
Another distinguishing feature is pupil shape; water snakes typically have round pupils, whereas cottonmouths, like other pit vipers, have vertical, cat-like pupils. A cottonmouth’s eyes cannot be seen when viewed directly from above because of scales covering them, but a water snake’s eyes are visible. Cottonmouths also possess heat-sensing pits between their eyes and nostrils, which water snakes lack, enabling them to detect warm-blooded prey even in low light conditions, though these are difficult to discern from a safe distance. When threatened, a cottonmouth may display the white interior of its mouth, a behavior that gives it its common name.
When encountering a snake, observe from a distance and avoid provoking it. Snakes typically bite only when threatened, cornered, or handled. If a snake is encountered while swimming, slowly move away, allowing it ample space to retreat. Wearing protective footwear, such as water shoes, can offer protection in shallow waters. Avoid swimming in murky waters or areas with dense vegetation where snakes might be hidden.