Tennessee is home to a diverse population of reptiles, with over 30 distinct snake species recorded across the state’s varied landscapes. Residents and visitors frequently encounter these creatures, which range from small, secretive burrowers to large constrictors. Understanding the differences between these species is important for respecting the natural environment and ensuring personal safety. While the vast majority of snakes found in Tennessee are harmless, a few species possess venom that requires caution. Learning the specific characteristics of the most common snakes can replace fear with informed awareness.
Identifying Tennessee’s Venomous Species
Tennessee is home to four venomous snake species, all of which belong to the family of pit vipers. These snakes share characteristics like a broad, triangular head, heat-sensing pits located between the eye and nostril, and pupils that are elliptical, appearing as a vertical slit.
Copperhead
The Copperhead is the most commonly encountered venomous snake. It is identifiable by its distinctive hourglass-shaped crossbands set against a tan or pinkish-brown background. The pattern is often described as “Hershey’s Kisses” when viewed from the side. This species typically reaches 24 to 36 inches and prefers wooded hillsides, rocky areas, and abandoned debris piles. Copperheads are generally mild-tempered and often remain motionless or vibrate their tail in dry leaves rather than immediately striking.
Timber Rattlesnake
The Timber Rattlesnake is the largest of the state’s venomous species, often growing 35 to 60 inches long with a heavy, robust body. Its appearance is marked by dark crossbands on a lighter base color of pale gray or yellowish-tan, culminating in the unmistakable rattle at the tail’s end. Despite its size and potent venom, the Timber Rattlesnake is known for its non-aggressive nature, relying on camouflage and its warning rattle to deter threats.
Western Cottonmouth
The Western Cottonmouth, also known as the Water Moccasin, is strongly aquatic and primarily found west of the Tennessee River. Adult Cottonmouths are heavy-bodied and can be dark olive, brown, or nearly black, with a large, blocky head. When threatened, this snake performs a characteristic display, opening its mouth wide to reveal the startling white, cotton-like lining that gives it its name.
Pygmy Rattlesnake
The Pygmy Rattlesnake is the smallest of the vipers, rarely exceeding 24 inches in length. It has a light brown or pinkish-tan body with dark dorsal blotches. Its tiny rattle produces a faint, insect-like buzz that is difficult to hear, making it a more subtle threat. This species is found in specific, localized habitats, such as riverine areas along the Tennessee River Valley.
Widespread and Harmless Snakes
The majority of snakes encountered in Tennessee are harmless.
Gray Ratsnake
The Gray Ratsnake is a large constrictor, reaching up to six feet long and found statewide. Sometimes called the Chicken Snake, it is an excellent climber, identifiable by its “loaf-of-bread” body shape and faintly keeled scales. The Ratsnake’s belly features a distinct white and black checkerboard pattern. Its diet focuses on rodents and bird eggs, making it a natural pest controller.
North American Racer
The North American Racer is often confused with the Ratsnake but has a very different physique. The Racer is noticeably more slender and agile, with smooth, shiny scales and a solid black body. Unlike the Ratsnake, the Racer is known for its speed and its tendency to hold its head high off the ground while hunting, a behavior called periscoping.
Eastern Kingsnake
Kingsnakes are known for their ability to prey upon other snakes, including venomous pit vipers, due to their immunity to the venom. The Eastern Kingsnake is a shiny, muscular constrictor that typically grows to three or four feet. It is distinguished by a glossy black body with narrow yellow or white crossbands that can form a chain-like pattern. This species is widespread and thrives in many habitats, from forests to agricultural areas.
Northern Water Snake
The Northern Water Snake is frequently mistaken for the venomous Cottonmouth, often leading to the needless killing of this harmless reptile. The Water Snake has round pupils and a more slender head that is not distinctly wider than its neck, contrasting sharply with the Cottonmouth’s triangular head and elliptical pupils. Its body is marked by dark crossbands or square blotches that are more pronounced toward the tail. It often flees quickly or dives underwater when disturbed.
Common Garter Snake
The Common Garter Snake is perhaps the most widespread species, found in almost every Tennessee habitat, including suburban yards and parks. It is a medium-sized snake, usually 18 to 26 inches long. It is easily recognized by the three light-colored longitudinal stripes—one down the back and one on each side—running the length of its dark body. This snake feeds primarily on earthworms, slugs, and amphibians.
Regional Distribution and Ecological Importance
The distribution of Tennessee’s snake species is closely linked to the state’s diverse geography, spanning from the Mississippi River lowlands to the Appalachian Mountains. The Western Cottonmouth and the Pygmy Rattlesnake are largely restricted to the western third of the state, thriving in swampy, riverine, and floodplain habitats. The Pygmy Rattlesnake is concentrated in the Lower Tennessee River Valley, where it is classified as a Threatened species due to habitat loss.
In contrast, the Timber Rattlesnake and the Copperhead are found across the entire state. They are often most common in the rocky, wooded slopes and mountainous regions of Middle and East Tennessee. Harmless species, such as the Gray Ratsnake and the Eastern Kingsnake, are also found across all three grand divisions, demonstrating their ecological resilience.
Snakes play a necessary role in maintaining the balance of the ecosystem, primarily through population control of small mammals.
Ecological Contributions
- Their consumption of rodents, such as mice, rats, and voles, helps naturally regulate populations that could otherwise cause agricultural damage or spread disease.
- Snakes serve as a food source for other wildlife, including birds of prey like hawks and eagles, as well as mammals.
The conservation of these reptiles is an ongoing concern. Many non-venomous species are mistakenly killed or suffer from habitat fragmentation, despite their significant environmental contributions.