Most snakes are not venomous and most snakes will not bite you unless you pick them up. Having said that, there are circumstances in which knowing the difference between snakes has saved people in the past. Learning these differences is important not only to your life, but to the lives of these snakes as well, because it is fear of all snakes that leads many people to kill any snake that crosses their paths. In the column below, you can identify the main differences that set these snakes apart.

The prime reason that every person should know the venomous snakes of his region by sight and know something about their habits, distribution, and abundance is that it will ease the mind of the average individual in all of his outdoor pursuits. Most persons have heard so many false stories about snakes that they develop a fear of all snakes. This fear is unfounded! A person who knows what venomous snakes he can expect to encounter in a given area need only learn to identify these and realize that all other snakes, lizards, frogs, toads, salamanders, and turtles do not have a venomous bite, and, therefore, he need not fear them. With a knowledge of the venomous snakes, a person can avoid places where these snakes might be found. Another aspect is the conservation of snakes. Too many people kill snakes just because they happen to be snakes. This is uncalled for destruction – a non-venomous snake should no more be killed than a song bird. In many cases, the harmless snakes are of direct economic value.
The non-venomous snakes far outnumber the venomous kinds, both in number of species and individuals. In the United States, there are approximately 95 species of nonvenomous snakes and only 19 species of venomous ones, including 15 rattlesnakes, one copperhead, one cottonmouth, and two coral snakes.
SNAKE BITE: Venom is secreted from glands within the head, on each side behind the eyes, causing the swollen appearance of the head in this region. The venom travels through ducts to each of the two fangs. The fangs are enlarged teeth in the front of the upper jaw. They are hollow, with one end connected to the poison duct and the other end having an opening on the front edge near the tip. The fangs are also fastened to a moveable bone, which enables the fangs to be folded back against the upper jaw when the mouth is shut and erected and directed forward when the mouth is opened to strike. The power of a strike imbeds the fangs into the skin of the victim, and muscles force venom from the glands through the duct and hollow fang and out of the opening at the tip. The venom causes a breakdown of the red blood corpuscles and walls of blood vessels. It also has an effect upon the nervous system. Some snakes have venom which is much more destructive to the nervous system. The pit vipers have venom which is more hemotoxic (destructive to blood), whereas the coral snake, which belongs to the cobra group, has a venom which is neurotoxic (destructive to nerves).
It has been estimated that there are fewer than 50 deaths due to snake bite in the United States in a year; most of these bites result from imprudent handling of venomous serpents. Most victims are less than 20 years of age and most bites occur on the hands, feet, arms, or legs.
HOW TO TELL A VENOMOUS FROM A NON-VENOMOUS SNAKE
VENOMOUS
Pupil of eye elliptical (cat-like)
Pit between eye and nostril
Two enlarged teeth (fangs) in front of the upper jaw
Scales on underside of tail in a single row
NON-VENOMOUS
Pupil of eye round
No pit between eye and nostril
All teeth of upper jaw approximately same size
Scales on underside of tail in a double row
KEY TO VENOMOUS SNAKES
I. No rattle or button on end of tail
Color pink-brown to red-brown with 10-20 light-edged crossbands on body, narrow on top and wider at lower side. Dark spot coinciding with and between each crossband at lower edge of side. Top of head copper-colored – COPPERHEAD
Always in vicinity of water. Pattern generally obscured by dark grey or black. If pattern is obvious, crossbands not narrow on mid-back and top of head not copper-colored – COTTONMOUTH.
II. End of tail provided with a button or rattles.
Top of head provided with paired plates, dark colored, small size – MASSASAUGA.
Top of head covered with numerous small scales; no paired plates
(a) tail pattern alternating black and chalk white bands – WESTERN DIAMOND-BACK RATTLER.
(b) tail pattern same as rest of body – PRAIRIE RATTLER.
(c) tail entirely velvety black – TIMBER RATTLER.
PRECAUTIONS
Don't step over logs. Step on top and look before stepping down.
When climhing rocky ledges or turning over logs or rocks, don't place hands where you can't see.
When walking among leaves, rocks, or grass, look before you step.
Don't keep venomous snakes.

Now, just because you correctly identify a venomous snake doesn't mean you should attempt to kill it. There's no reason to approach it, and the action of trying to rid an area of a dangerous snake is what gets most people bitten in the first place (what goes around comes around).

If you're out in the wilderness just leave it be, but if it's on your property and you're concerned about your pets or kids, call animal control so they can take it back out into the wild. Also, if you get bit, don't think you can improve your chances by doing the Hollywood cut-and-suck method on the bite, or even a tourniquet; they don't work.

Blood only takes 18 seconds to make it all the way through the body and nothing you do going to keep that venom from circulating. Your only bet is to remain calm and get to a hospital as quickly as possible.

If you'd like to learn more about these snakes, take a look at the original article on Emporia (Disclaimer: some of the information is outdated).