The Tennessee Wildlife Resources Agency declares the timber rattlesnake is in great need of conservation. Timber rattlesnakes, or Crotalus horridus, are shy creatures and only bite humans if they feel threatened. Timber rattlesnakes only inject a portion of the venom when they bite since they do not want to run out of venom. The West Meade Conservancy claims the best way to avoid encounters with timber rattlesnakes is to remove all food and drink from your yard, clear fallen logs and repair leaky garden hoses. Timber rattlesnakes live throughout Tennessee.
Two subspecies of copperheads live in Tennessee: northern and southern copperheads. Most copperhead snakes in Tennessee are the northern subspecies. Northern copperheads live throughout the state, while southern copperhead populations are restricted to southeast Tennessee. The Tennessee Herpetological Society states the most frequent venomous snakebites come from copperheads, even though it is rare for copperheads to bite humans. Copperheads, or Agkistrodon contortrix, grow between 2 to 3 feet as adults. Although they do not have rattles, copperheads will shake their tails before attacking a potential predator or human. During the summer, these snakes are nocturnal, but copperheads are active in the day during the spring and fall.
Also known as Sistrurus miliarius, the pygmy rattlesnake is a venomous snake found in the semi-aquatic habitats near the Tennessee River Valley in western Tennessee; pygmy rattlesnakes are especially abundant in the Land Between the Lakes National Recreation Area in northwest Tennessee. The Tennessee Wildlife Resources Commission considers this snake a threatened species. Pygmy rattlesnakes are the smallest venomous snakes in Tennessee; when fully mature, these snakes grow up to 1.5 to 2 feet.
One subspecies of cottonmouths, the western cottonmouth, lives in the Tennessee River Valley, located in the West Central region of Tennessee. The western cottonmouths, or Agkistrodon piscivorus leucostoma, is also known as a "water moccasin," since it lives in aquatic habitats and has a thick body structure. Unlike non-venomous water snakes, cottonmouths swim on the surface of water; non-venomous water snakes submerge themselves when swimming. When they open their mouths, cottonmouths have entirely white skin; cottonmouths will open their mouth as a warning to potential predators. As adults, western cottonmouths grow between 3 to 5.5 feet long.