Tennessee is home to 32 species of snakes, only 4 of which are venomous. All of the venomous snakes native to Tennessee belong to the family of snakes called pit vipers. Pit vipers are the group of venomous snakes having a specialized, heat sensing pit on the front of the head. There are four species of pit vipers in Tennessee: Copperhead, Cottonmouth, Timber Rattlesnake and Pigmy Rattlesnake.

Venomous: vertical, elliptical pupil, facial pit between eye and nostril; & in comparison to other snakes they are very stout or thick-bodied, consequently they are poor climbers. Tennessee’s venomous snakes have a head that is offset from the rest of the body. In many non-venomous species, it is hard to tell where the neck ends and the head begins; however many non-venomous species may flatten their heads into the arrowhead shape when they feel threatened.

Note: Many non-venomous snakes will mimic venomous species when confronted. Mimicry may include the rapid vibration of tails (rattler-like), spreading the jaws to appear venomous, coloration and patterns that closely mimic venomous species, using an s-shaped strike stance, and rearing up and hissing loudly.

The Eastern Timber Rattlesnake is one of the most dangerous venomous snakes in northeastern United States. However, bites are not common. This rattlesnake normally is calm, preferring to stay coiled and motionless when approached, or to crawl away when bothered. If threatened though, the Eastern Timber Rattlesnake will rise up and shake its rattle, giving a threat or warning before striking. Generally, rattlesnakes can strike as much as 1/3 to 1/2 of their body length.
When born, the young rattlesnake has a single "button" at the end of its tail. As the snake grows it sheds its skin, thereby allowing for further growth in both length and girth. With each shed a new segment is added to the "rattle." Often, an older snake loses its original button through wear. The segments, usually more than five or six on a large adult, are loosely attached to each other. When the rattlesnake vibrates its tail these segments shake against one another, making the rattle sound. The noise is a very rapid, crisp, rattling vibration. Some people compare the sound to that made by certain nighttime insects. Others say it sounds like a vibration in dry leaves. The Eastern Timber Rattlesnake is diurnal in the spring and fall but it become nocturnal during the hot summer months. In the winter, it usually hibernates with a number of snakes, including such other species as the Black Rat Snake and the Copperhead Snake .Rattlesnakes come into residential areas for two reasons: food and cover. Therefore, you should eliminate the food attraction by keeping your home free of mice and rats. Eliminate rattlesnake cover attraction by avoiding tall ground cover and moving hiding places such as large rocks or rubbish.

Copperheads get their names, quite logically, from their un-marked, copper-red colored heads. Copperheads have light-brown, or orange, or pink bodies that are highlighted by dark, chestnut brown cross bands which form a series of hourglass shapes across their backs. The thickness and continuity of these cross bands are important characteristics in identifying the five sub-species . Belly markings of these snakes consist of gray to black blotches that are blended together to make a cloudy or marbled pattern. Copperheads are typically 2 to 3 feet in length although individuals up to 4 ½ feet long have been reported. Females are longer than males, but males have proportionally longer tails. The bodies of copperheads are stout and taper abruptly to form the much smaller diameter tail. Immature copperheads have tails that are bright yellow, and they may use these colored tails to attract prey.
Copperheads can thrive in a variety of habitats including rocky, wooded areas, wood and sawdust piles, mountains, brushy zones along streams and creeks, abandoned farm buildings and old foundations, junk yards, swamps, brush piles, and desert oases and canyons. Copperheads are usually solitary except during their mating season. They do hibernate in communal dens, though, not only with other copperheads but also with snakes of a variety of species (including rat snakes and rattlesnakes). In the spring and fall copperheads can be frequently seen during the day, but in the warm summer months they are primarily nocturnal. Humid, warm nights, especially nights after a rain, are ideal times to see active copperheads

Cottonmouths are very heavy-bodied, semi-aquatic pit vipers with dark cross bands on an olive to dark brown background. Young cottonmouths are often reddish brown and thus resemble their close relative, the copperhead. Adult cottonmouths are considerably darker than juveniles and can sometimes be entirely black. Like copperheads, young cottonmouths have yellow tails which they wiggle to lure unsuspecting frogs and lizards.
The cottonmouth gets its name from the white coloration inside the mouth that they open wide as a threat towards potential enemies. Cottonmouths are often referred to as “water moccasins,” as are non venomous water snakes, a species with which they are often confused. Though often perceived as aggressive, cottonmouths usually try to escape or dissuade their enemy before biting. Besides gaping the mouth, the cottonmouth will also vibrate the tail, flatten the body to make themselves look bigger, and release foul smelling musk from scent glands near the tail. A cottonmouth's venom is very toxic and bites can be severe.