An average of five people are each year killed due to venomous snake bites in the USA (Gold et al., 2002)1. Approximately 8,000 venomous snake bites are reported each year, in the US, and the total number of bites is estimated to 45,000 (ibid) although other claims this number to be lower (Litovitz et al., 1997)2.
According to official statistics, only 18 percent of snake bites in the USA are from venomous species.
Medical symptoms from venomous bites vary a lot. Besides wound discharge some of the symptoms associated with envenomations are the same as in severe cases of flu.
According to an article by Sutherland (1992)3, where fatalities from snake bites over a 10 year period in Australia were studied, only 18 snake bites had a deadly outcome (see later) in that 10 year period. The author states that it is likely that not all lethal cases have been reported.
Only four species poses a hazard to humans in the US, and the venomous species found in USA are not among the most venomous snake species of the world.
In South and Central America, bites from venomous species are a worse problem than in the US. In Costa Rica the annual number of hospital admissions because of snake bites is 22.4 per 100,000 inhabitants (Rojas et al., 1997)4.
When compared to how many are killed by lightning each year, which in a period from 1959 to 1994 was 0.42 people per million USA citizens (Curran et al., 1994)5, injuries caused by snakes seems to be a minor problem.
This fact doesn’t cause snakes and especially venomous bites to be less interesting. This webpage is dedicated to venomous snakes, their habitat, ecology, life-cycle, how to avoid bites, specie descriptions and much more.
The site also contains some videos and pictures such as the video below.
Poisonous Snakes – a technical misunderstanding
The correct term to use is venomous. Normally venom is harmless if ingested but if the venom is injected into some tissue it is toxic and the tissue around the site of injection and other parts of the body will suffer one way or another.
Below is a overview of some of the species presented here:
Rattlesnakes, Crotalus sp., comes in different varieties and there are numerous sub species and color variations. One thing rattlesnakes do have in common is jointed rattles on their tail.
In the section about rattlesnakes you’ll find detailed descriptions of the most common rattlesnakes in USA. A bite from a rattlesnake can be deadly.
The cottonmouth snake is also known as the water moccasin and is sometimes confused with the water snake The name cottonmouth comes from the fact that its mouth looks like cotton when it opens its mouth. This snake has been considered aggressive, but studies have proven that wrong. Cottonmouths reach a length of approximately 30-48 inches. The Cottonmouth Snake is one of the most common snakes in Florida. Other Florida Snakes includes the three other not very deadly US snakes also described on this website.
Coral snakes are easy to recognize from their alternating black, red and yellow bands. They are usually shorter than 40 inches. Their preferred place of staying is beneath debris or flatwood, or anywhere that offers some kind of sheltor.
Black Mamba Snakes
Black mamba snakes are some of the most venomous snakes in the world. It is also one of the largest, in fact the longest venomous snake in the world. Recently a man from Florida was bitten by a green mamba.
A Copperhead Snake is even shorter than both the coral and cottonmouth snake. It is the most often encountered snake in Eastern states like Alabama, Missouri and Arkansas, but of course also all other states. Copperheads are responsible for most venomous snake bites in the USA. Bites are however the last line of defence for the copperhead.
Sea snakes are closely related to Cobras. True sea snakes, as some herpetologist call them, only live in water. They have adapted to a life in water and have small flattened heads that minimizes water resistance when they swim. Their favorite food is fish.
This is perhaps the most dangerous (but not the most poisonous snake) snake in the world when it comes to person envenomations. Under conditions of high prey availability they can reach a length of six feet. Prey is completely paralyzed by its venom making any resistance virtually impossible.
Snakes in general
Snakes serve an important role as predators in the ecosystems, and snakes are signs of a healthy ecosystem. They help maintain populations of rodents and other prey at a constant and acceptable level. Just think of farmers and the problems they got with rodents. Snakes are actually responsible for keeping crop yields at an acceptable level and preventing spreading of diseases by killing rats. Snakes such as the non-venomous rat snakes are excellent at doing this.
Avoiding snake bites
There are some simple rules to follow that will minimize the risk of being bit a snake. If you follow these simple three rules the risk of having poison injected into your body by a snake will decrease dramatically.
- Don’t try to handle a snake if you don’t have any formal training in doing so.
- Stay away from tall grass – remain on hiking paths.
- Avoid rock climbing or be very cautious climbing in rocks.
Symptoms of a venomous bite
You should probably know when a snake has injected its venom into your tissue. Here is however, a list of common symptoms often encountered from a poisonous snake bite.
Each individual will experience symptoms somehow differently. The following symptoms are the most often reported.
- Discharge of blood from the wound
- Marks in the skin and swelling at the site of the snake bite
- Severe pain around the bite site
- Convulsion of varying severity
- Blurred vision, weakness, dizziness and fainting
Antivenin can be administered at any hospital.
1 Gold, BS et al. “Bites of Venomous Snakes”. New England Journal of Medicine Vol. 347, No. 5 pp. 347-356 (2002)
2 Litovitz TL et al. “Annual report of the American Association of Poison Control Centers Toxic Exposure Surveillance System” Am J Emerg Medicine 15, page 447-501 (1997)
3 Sutherland SK “Fatalities from Snake Bite in Australia, 1981-1991”, MED. JOURNAL OF AUSTRALIA 157 Vol. 11-12. pp. 740-746 (1992)
4 Rojas G et al. “Snakebite mortality in Costa Rica”, Toxicon, Vol. 35 pp. 1639-43 (1997)
5 Curran EB. et al. “Lightning injuries and Damage Reports in the United States from 1959-1994” (1997), NOAA Technical Memo-randum
Australia’s venomous snakes
Utah State University (pdf)
Snakes of South Africa