Tennessee is home to over 30 native snake species, most of which are harmless and beneficial to the state’s ecosystems. The state’s diverse habitats, ranging from high mountain forests to extensive river systems, support a variety of wildlife, including a small number of species that possess the ability to deliver venom. Understanding which snakes are venomous and where they live is important for safe coexistence, especially during warmer months when human and reptile activity increases.
The Total Count and Specific Species
Tennessee is home to four distinct species of venomous snake, all belonging to the Crotalinae subfamily, commonly known as pit vipers. This group includes the Copperhead, the Cottonmouth (Water Moccasin), the Timber Rattlesnake, and the Pygmy Rattlesnake. All four species are equipped with specialized fangs and heat-sensing pits.
The Copperhead is the most widely distributed, found across the entire state, and is responsible for the majority of reported snake bites in Tennessee. The Timber Rattlesnake is more secretive, preferring heavily wooded or mountainous terrain. The Cottonmouth and the Pygmy Rattlesnake have restricted ranges within the state.
Geographic Distribution Across Tennessee
The distribution of these four venomous species is closely tied to specific habitat types across the state’s three grand divisions. The Copperhead is the only species that occurs in all regions, inhabiting rocky, wooded hillsides and often adapting to suburban environments. Two subspecies are present, with the Southern Copperhead confined to the extreme western portion of the state.
The Cottonmouth, the state’s only venomous water snake, is largely restricted to West Tennessee and the western reaches of Middle Tennessee, generally west of the Tennessee River. These heavy-bodied snakes prefer aquatic habitats such as swamps, river floodplains, and sloughs.
The Pygmy Rattlesnake also has a limited range, found mostly along the floodplains of the Tennessee River and in the western reaches of the state, favoring marshy areas and wet prairies. The Timber Rattlesnake is most common in the mountainous, heavily forested regions of East Tennessee and the rugged terrain of the Highland Rim. They often occupy rocky outcroppings and forests.
Identifying Features of Pit Vipers
Distinguishing venomous pit vipers from harmless snakes involves observing several key morphological features. All pit vipers possess a triangular head, which is noticeably wider than the neck due to the location of their venom glands. They also have loreal pits, which are small, deep depressions located between the eye and the nostril on each side of the head.
These pits function as highly sensitive infrared-detecting organs, allowing the snake to sense the heat signature of warm-blooded prey. Pit vipers in Tennessee typically have vertical, elliptical pupils, while most non-venomous species have round pupils. A definitive feature is the arrangement of the subcaudal scales on the underside of the tail past the anal plate. In pit vipers, these scales are arranged in a single, undivided row, whereas most non-venomous snakes have scales divided into two rows.
Safety Measures and Encounter Protocol
Preventative measures significantly reduce the likelihood of a venomous snake encounter when hiking or working outdoors. Wearing thick, high leather boots or gaiters offers substantial protection against a bite. Avoid stepping over logs or large rocks without first checking the other side, as snakes often hide or bask there. Clearing brush, tall grass, and debris piles from residential yards removes potential hiding spots.
If a snake is encountered, remain calm and slowly back away, giving the snake ample space to retreat. Never attempt to handle, harass, or kill a snake, as this is when most bites occur. In the event of a bite from a venomous snake, call 911 or emergency services immediately.
While waiting for medical help, keep the bitten limb still and positioned at or slightly below the level of the heart to slow the spread of venom. Remove any jewelry, watches, or tight clothing from the area before swelling begins. Crucially, avoid the following actions, as they can cause more harm than good and delay appropriate medical treatment:
- Applying a tourniquet.
- Cutting the wound.
- Attempting to suck out the venom.
- Applying ice.