Common Watersnake
Nerodia sipedon • Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: Nerodia sipedon
Widespread across North America, from southern Ontario and Quebec in Canada throughout the eastern and central United States, as far south as Texas and Florida and west to Colorado.
Look up Common Watersnake in the Snake Encyclopedia →Venomous Status
Non-venomous; lacks fangs or venom-delivery apparatus.
Danger Level
Low Risk / Harmless; though they are non-venomous, they are famously defensive and will bite repeatedly and musk if handled. Bites may bleed profusely due to anticoagulants in saliva but are not dangerous.
Family
Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Nerodia, Species: Nerodia sipedon
Conservation
IUCN Least Concern. Highly adaptable and abundant, though often killed by humans who mistake them for venomous Cottonmouths.
Physical Description
Heavy-bodied snake with dark brown, tan, or grayish coloration. Younger individuals have distinct crossbands near the head that break into alternating dorsal and lateral blotches further down the body. Scales are heavily keeled, and eyes have round pupils. Ventral scales often have dark, reddish half-moon shapes.
Size & Dimensions
The specimen appears to be an adult approximately 2 to 3 feet in length. Species typical range is 24 to 42 inches (61–107 cm), with a maximum recorded length of 59 inches.
Habitat
Semiaquatic; found in lakes, ponds, rivers, marshes, and canals. Prefer slow-moving or standing water with plenty of basking sites such as rocks, logs, or overhanging vegetation.
Behavior & Temperament
Diurnal and crepuscular; active during the day basking or foraging. Highly defensive when cornered: they will flatten their heads to appear larger, strike vigorously, and release a foul-smelling musk and feces. Excellent swimmers that typically dive underwater to escape threats.
Diet & Feeding
Generalist carnivore focusing on aquatic and semiaquatic prey. Primarily feeds on fish and amphibians (frogs, toads, tadpoles). Hunting involves active foraging or 'gulping' through shallow water to catch prey.
Reproduction
Viviparous (gives birth to live young). Mating occurs in spring; females give birth to 15–30 young (sometimes up to 100) in late summer or early autumn.
Venom Profile
Non-venomous - no medically significant venom. Saliva may contain mild anticoagulants.
Look-alikes
Often confused with the venomous Cottonmouth (Agkistrodon piscivorus). Distinguishable by round pupils (vs. vertical), lack of heat-sensing pits, and labial scales with dark vertical bars (which Cottonmouths lack). Also resembles other Nerodia species like the Plain-bellied Watersnake.
Conservation Status
IUCN Least Concern. Highly adaptable and abundant, though often killed by humans who mistake them for venomous Cottonmouths.
Cultural Significance
Often maligned due to its irritable temperament and resemblance to venomous snakes. Ecologically vital as a mid-level predator that controls fish and amphibian populations.
Notable Features
Features heavily keeled scales that give the snake a rough texture. Their ability to remain submerged for extended periods and their specialized diet makes them one of the most successful semiaquatic reptiles in North America.