The water moccasin, also known as the cottonmouth (Agkistrodon piscivorus), is a venomous pit viper found across the southeastern United States. It commonly inhabits moist forests, wetlands, and aquatic environments like swamps, marshes, ponds, and streams. While often associated with water, these snakes can also be found on land, sometimes venturing far from water sources. Understanding its characteristics and behavior is important.
Identifying the Water Moccasin
Distinguishing a water moccasin from other non-venomous water snakes is important. Water moccasins typically possess a broad, triangular head distinctly wider than their neck. They also have vertical, cat-like pupils and heat-sensing pits between their eyes and nostrils.
Their coloration varies, ranging from dark brown or black to olive, tan, or gray, often with darker crossbands. Juvenile water moccasins often display more vibrant patterns and have a bright yellow or greenish tail tip. When threatened, a water moccasin may coil its body and open its mouth wide, revealing the strikingly white interior, giving it the name “cottonmouth.” Unlike many non-venomous water snakes that submerge most of their bodies, water moccasins often swim with their entire body floating on the surface.
The Nature of Its Venom
The water moccasin’s venom is primarily hemotoxic, meaning it affects the blood and tissues. This venom works by breaking down blood cells and preventing blood from clotting, which can lead to significant tissue damage, internal bleeding, and extreme pain at the bite site. Common symptoms following a bite include immediate, burning pain, rapid swelling, bruising, and skin discoloration around the wound. Blistering and tissue death, or necrosis, can also occur in more severe cases.
While a water moccasin bite is painful and can cause severe injury, fatalities are rare. Approximately 7,000 to 8,000 people are bitten by venomous snakes in the U.S. each year, but only about five to six deaths occur annually, with cottonmouths accounting for less than 1% of these. Some bites may even be “dry bites,” where no venom is injected. However, untreated bites can lead to complications such as infection or extensive tissue damage, necessitating prompt medical attention.
Safety and Emergency Actions
Avoiding encounters with water moccasins involves awareness of their preferred habitats. Avoid dense vegetation near water, watch where you step, and never place hands or feet into unseen areas. Maintain a safe distance from any snake, ideally at least six feet. Provoking or attempting to handle a snake significantly increases bite risk.
Immediate medical attention is necessary if a water moccasin bite occurs; call emergency services and remain calm. Move away from the snake, and remove any jewelry or constrictive clothing from the bitten limb before swelling begins. Keep the bitten area still and, if possible, below the heart to slow venom spread. Clean the wound gently with soap and water, then cover it with a clean, dry dressing. Do not apply a tourniquet, cut the wound, attempt to suck out venom, or apply ice, as these actions can worsen the injury.