Humans seem hard wired to fear of snakes, and it is useful to help us be cautious around poisonous species. But the vast majority of snakes found in our area is harmless, and perform a useful service of keeping rodent populations in check. There are two poisonous varieties in our woods where caution is advised.
Poisonous snakes are grouped together in a category known as pit vipers. This comes from the deep pit on each side of their head, which is actually a heat sensor and helps them sense and locate warm-blooded prey. These pits are not always obvious, so I wouldn’t use them to identify whether or not a snake is poisonous. Some features to look for in identifying pit vipers include a head that is larger than the neck (protruding jaws), and the eyes have vertical slits like those of a cat, as opposed to non-poisonous snakes which have round pupils. Here is a short description of the poisonous snakes in our area.
Rattlesnake: The fact that this reptile has a warning device on the end of its tail is well known. The rattle is actually a modified collection of scales that when shaken will produce a loud buzzing noise. Many other snake species will shake their tail when confronted, and if the tail happens to strike dry leaves, the resulting noise may be suggestive of a rattlesnake. Of the 15 kinds of rattlesnakes in the US, only the Timber Rattlesnake is found in our area. It is usually 3-6 feet long, and has two color phases. One is a yellow phase where the body is a dull yellow color with black or brown bands around the body. The other is the black phase, where the body has splotches of black and brown with no distinct pattern. The Timber Rattlesnake prefers second growth woodlands where rodents are plentiful. Like all pit vipers, rattlesnakes congregate together in sheltered dens to hibernate during the winter.
Copperhead: The Northern Copperhead is the one found in our area. There is also a Southern Copperhead more common in Florida and southern Georgia. Ours has a coppery red head with red and brown bands along the body (average length 2-3 feet). The copperhead is well camouflaged and hard to see on the forest floor. They tend to remain very still even when approached, and I have almost stepped on one more than once. Rocky, wooded hillsides and mountains are their favorite hangouts. Copperheads feed mainly on mice, along with and occasional small bird, frog, or insect. When confronted they will strike vigorously and shake their tail.
Some claim that we have Cottonmouth snakes as well, but their natural range in west of Nashville. Since we’re fairly close, I’ll include it. The reptile is usually black in color and around 2-4 feet long. The cottonmouth can be aggressive and is considered dangerous. When confronted it will vibrate its tail against the ground and may throw its head back and open the mouth very wide, exposing a white interior (hence the name). The cottonmouth likes swampy places where it can catch fish, frogs, small birds, and other snakes.
I know in the adrenaline rush of seeing a snake people want to kill any and all found. But as mentioned most are harmless and play a huge role in controlling rodent populations, so if you can give snakes their space when seen in the woods and live and let live, it would be an environmentally friendly act.