The term “black snake” is a common, descriptive label used across North America for any snake species with predominantly dark or black coloration. This catch-all phrase encompasses several distinct species and is not a formal scientific classification. Because many non-venomous snakes share this dark hue, and some venomous species can also appear black, this general description often leads to confusion.
The Two Most Common Black Snakes
The majority of “black snake” sightings involve two non-venomous species: the Eastern Rat Snake and the Eastern Black Racer. The Eastern Rat Snake (Pantherophis alleghaniensis), sometimes called the Pilot Black Snake, is a large, heavy-bodied constrictor that can reach lengths between three and seven feet. This snake is an exceptional climber, frequently found scaling trees or rafters in barns for rodents and bird eggs. Its dorsal scales are weakly keeled, giving it a slightly rough texture, and its underbelly is typically a mottled pattern of white, gray, and black.
The Eastern Black Racer (Coluber constrictor) is generally more slender and shorter, typically measuring between three and five feet in length. True to its name, this species is known for its speed and tends to flee rapidly when approached, contrasting with the Rat Snake’s tendency to freeze defensively. The Racer has a uniform, glossy black appearance with smooth scales. Unlike the Rat Snake, the Racer is an active, diurnal hunter that does not constrict its prey, instead overpowering and swallowing small animals alive.
Other Regional Black Snakes
Beyond the two most common species, several other snakes are regionally black or possess a dark phase that leads to the same common name. The Eastern Indigo Snake (Drymarchon couperi), found in Florida and southern Georgia, is a large, non-venomous species with an iridescent, uniform bluish-black coloration and smooth scales. This snake is the longest native species in the United States, occasionally exceeding eight feet, and is known for preying on other snakes, including venomous ones.
In the arid regions of the Southwest, particularly Arizona and northwestern Mexico, the Mexican Black Kingsnake (Lampropeltis getula nigrita) is a popular example of a jet-black snake. This species has smooth, highly lustrous scales and can reach lengths of four to five feet, feeding largely on rodents and other reptiles. Many aquatic snakes, like the Common Water Snake (Nerodia sipedon), can darken dramatically with age, appearing almost solid black or dark brown. These Water Snakes, which are heavy-bodied and have keeled scales, are often found basking near water sources throughout the eastern and central United States.
Identifying Black Snakes and Misidentification
Distinguishing harmless black snakes from potentially dangerous look-alikes involves observing a few distinct physical and behavioral characteristics, primarily from a safe distance. Most non-venomous snakes native to North America have round pupils and a double row of scales on the underside of their tail after the vent. In contrast, venomous pit vipers, such as the Cottonmouth, Copperhead, and Rattlesnake, possess vertical, elliptical pupils and a single row of scales under their tail.
The most frequent misidentification occurs between non-venomous Water Snakes and the venomous Cottonmouth (Agkistrodon piscivorus), especially since mature Cottonmouths can be uniformly dark or black. While Water Snakes flee when threatened, a Cottonmouth is more likely to freeze or stand its ground, often displaying its white-lined mouth in a defensive gape. It is important not to rely on head shape alone, as many non-venomous species, including the Rat Snake, can flatten their heads to mimic the triangular shape of a venomous snake when they feel threatened.
Other dark-colored venomous snakes, like some dark-phase Timber Rattlesnakes, can appear black, but their tail will be solid black just before the rattle. Juvenile Rat Snakes are also sometimes mistaken for Copperheads due to their early blotched pattern, but the adult black snakes lose this patterning completely. If you encounter a snake and cannot identify it, maintain distance and allow the animal to move away on its own.