Once Bitten, Twice Shy. - Proverb

Venomous snakes found in the United States include rattlesnakes, copperheads, cottonmouths/water moccasins, and coral snakes. About 8,000 people a year receive venomous snake bites in the United States, and only 9 to 15 victims about 0.2% die. Most of the fatalities receive no medical treatment or first aid.

Crotalidae Family

There are three kind of the Crotalidae or pit viper snakes in the United States. The pit vipers include the copperhead, the cottonmouth or water moccasin, and rattlesnakes. They are called pit vipers because they have a pit or depression between the eye and the nostril on each side of the head, which functions as an extremely sensitive infrared heat-detecting organ.

Many pit viper strikes in fact are dry and inject no venom, even when there are fang marks. Part of this may be due to the fact that humans are much bigger and give off a lot more heat than the snake's usual prey, and this throws off the timing of the snake's venom delivery. Additionally, Crotalids can differ significantly in the toxicity of their venom, even within a single litter.


Have a heavy, triangular head with elliptical or cat's-eye pupils. They also have a rattle at the end of there tail, and generally they will let you hear it if you approach. There are 15 different species of rattlesnakes in North America. Rattlesnakes are the largest of the venomous snakes in the United States. They can accurately strike at up to one-third their body length.

U.S. Geographic Region: Across the United States. Rattlesnakes may be found sunning themselves near logs, boulders, or open areas.

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Cottonmouths (Water Moccasin)

One of the hardest venomous snakes to identify. They range in color from coppery brown to black to greenish, and can be solid colored, with vague black or dark brown crossbands. Cottonmouth snakes average 50-55 inches long. A white stripe along the side of their heavy, triangular head, and their elliptical or cat's-eye pupils all help to identify them. A juvenile or baby cottonmouth has a bright, sulfur-yellow tail. Younger cottonmouths are more brightly colored and show strongly banded patterns, adults tend to be duller and darker in coloration. Cottonmouths can be very aggressive. They do not scare easily and will defend themselves when threatened.

U.S. Geographic Region: Wetland areas, rivers, lakes, etc., in the southeastern states. Cottonmouths are often found in or near water, but are quite comfortable on dry land and can adapt very well to living inland.

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Are closely related to cottonmouths, with a similar body type but showing much brighter colors ranging from coppery brown to bright orange, silver-pink and peach. Look for a distinctive "copper" colored triangular head against a mostly brown or green body. The colored bands on their body are typically hourglass-shaped. Most adults are 18-36 inches long. Like cottonmouths, juveniles have bright yellow tails. They are not usually aggressive, but will often freeze when frightened. They are faster moving and more nervous than cottonmouths.

U.S. Geographic Region: Eastern states, extending as far west as Texas. These snakes are often found in wooded or hilly areas, and are attracted to shady areas that offer cover to hide under.

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Elapidae Family

There are three kind of the Elapidae or coral snakes in the United States. Micrurus fulvius (Eastern or common coral snake), Micrurus tener (Texas coral snake), and Micruroides euryxanthus (Arizona coral snake), found in the southern and western United States. Coral snakes found in other parts of the world can have distinctly different patterns, have red bands touching black bands, have only pink and blue banding, or have no banding at all.

While the pit viper venom reduces the amount of oxygen carried by a victim's red blood cells, a coral snake has venom that rapidly affects the nervous system. The small mouth of the coral snake has trouble grasping and biting the larger human; however, the effect is more deadly than the pit viper once a bite is accomplished.


Corel snakes in the Unitrd states are distinctively colored in black, yellow and red, with a solid black band on the nose and a bright yellow head. The old rhyme, "Red touch yellow, kill a fellow. Red touch black, friend to Jack," is only halfway accurate. Coral snakes are shy, inoffensive creatures which only bite if grabbed roughly, and sometimes not even then. There are no known deaths from the Arizona coral snake (Micruroides), and very few on record from the Eastern coral (Micrurus).

U.S. Geographic Region: Wooded, sandy, or marshy areas of the Southern United States. Coral snakes tend to hide in leaf piles or burrow into the ground.

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Visual Differences Between Venomous and Non-venomous Snakes

  • Venomous snakes in the US all have elliptical (slit) pupils like a cat's eye. Non-venomous snakes have round pupils. The exception to the rule is the Coral snake they do not have slit pupils.
  • Most venomous snakes in the US tent to have bodies with varying colors. Snakes that are one solid color are usually harmless. The exception here is the Cottonmouth.
  • Most venomous snakes tend to have a triangular shaped head due to the venom glands. Non-venomous snakes have spoon shaped heads. The Coral snake, being so small, makes this hard to spot.
  • If a snake is swimming with just its head above water, it's most likely to be a non-venomous water snake. Nearly all venomous swimming snakes swim with their lungs fully inflated causing their bodies to float on the surface of the water.


Try to remember the color and shape of the snake, which can help with treatment of the snake bite.

Pit viper venom is a complex mixture of enzymes, which varies from species to species, and which is designed to immobilize, kill, and digest the snake's prey. Pit viper strikes on humans are overwhelmingly on the extremities. Crotalid venom works by destroying tissue, and is capable of causing significant, sometimes disfiguring local tissue damage. Greater or smaller areas of the extremity can turn blue or black, swell alarmingly, and develop large blood blisters. Pit viper envenomation can be excruciatingly painful, and the discomfort can last for several days.

Crotalid envenomation is a medical emergency requiring urgent evacuation if possible. However, the first step in treatment is to avoid panic. Death is rare; even without evacuation, most cases result in several days of serious misery and then full recovery.

Remember that a snakebite is a contaminated puncture wound, and treat it as such. Even a non-venomous snake which eats small mice, such as a corn or rat snake, can cause a very serious cellulitis/skin infection due to the snake's saliva.

Steps to be taken for treatment:

Call emergency services immediately

  • Stay calm
  • The less the victim moves the bitten site, the less likely the venom will be spread through the body and cause damage.
  • Have the victim lie down with the affected limb lower than the heart.
  • Keep the limb immobilized. If practical, splint the limb.
  • Treat for shock and preserve body heat.
  • Remove any rings, bracelets, boots, or other restricting items from the bitten extremity. (It WILL swell.)
  • Apply a light constricting band about 2" above and below the bite, however never place the bands on either side of a joint (such as above and below the knee or elbow). This band should be made up of wide, soft material. NOTE: The purpose of constricting bands is to restrict lymphatic flow, not blood, so they should not be too tight. Check pulses below the bands and readjust the bands as necessary when they tighten due to swelling.
  • Wash the bite with soap and water (if available).
  • If the victim has to walk out, sit calmly for 20-30 minutes to let the venom localize at the site, then proceed calmly to the nearest source of help and try to avoid unnecessary exertion which will stimulate circulation of the venom.
  • Get the victim to definitive medical care for antivenin, which will provide the greatest relief from the toxic effects of the bite.

Steps not to be taken:

  • Make incisions or try to suck out the venom. In wilderness conditions, cutting into an already compromised limb is asking for an infection. The additional tissue damage may actually increase the diffusion of the toxins throughout the body.
  • Never try to suck out the venom by mouth.
  • Use a tourniquet. Tourniquets can result in loss of the limb due to decreased blood flow. In addition, you are just keeping the venom localized where it does the most tissue damage.
  • Use electric shock. It can be dangerous, and has no proven value in managing pit viper bites. It is the great urban legend of wilderness first aid.
  • Use cold and/or ice packs. There is no evidence that snake venom enzyme activity diminishes with cold. Freezing already compromised tissue can lead to frostbite, which can damage the limb more than the original bite. Recent studies indicate that application of cold or ice makes the injury much worse.
  • Give alcohol or caffine. It causes vessels to dilate and may speed venom absorption.

There are two questions regarding the treatment of Crotalid envenomation you should be aware of

1. The use of antivenom.
2. The use of an elastic bandage pressure wrap.

For many years, the only available antivenom in the United States for pit viper envenomation was Wyeth Laboratories Antivenin (Crotalidae) Polyvalent. This antivenom was made with horse serum, and patients were at risk for severe allergic reactions. However, a new antivenom, Crotalidae Polyvalent Immune Fab (Ovine), marketed by Savage Laboratories as CroFab, is made with sheep serum; CroFab reportedly has fewer adverse reactions than the Wyeth serum.

The use of an elastic bandage pressure wrap. The argument against its use is that the pressure may actually increase the risk of disfiguring local tissue damage, which may then require skin grafts and extensive repair and treatment; and that removal of the pressure may result in sudden massive swelling and discoloration. The argument in favor of its use is that the spread of venom to vital organs can be life-threatening, some Crotalid bites can cause serious damage to limbs even when the bites were to a finger or foot, and the use of a pressure bandage can prevent this spread. The tradeoff is between averting more serious life-threatening damage and increasing the risk of painful and disfiguring local damage. A decision to be considered with the victim.