Today I found out all snakes can swim.

If you’re one of those people who are afraid to swim in lakes, rivers, and the like, here’s another reason for you to stay out of the water: all snakes can swim.  Thus, all snakes are technically “water snakes”, even though only some are given that designation, usually due to their propensity to hang out near water.

Snakes swim by moving their body in lateral, wave-like movements, more or less appearing to shape their body in an S pattern.  These undulations start from their head and continuing down their body.  This is the same type of body movement they’ll use when moving on very smooth surfaces.  Using the S-shape movement propagating down their body, the snake can exert a force backwards against the water, which results in them moving forward.  Water snakes also use this method to swim, but these types of snakes often have more flattened sides than other snakes, which allows them to swim more efficiently using this motion over their rounded brethren.

It should be noted though that snakes aren’t nearly as dangerous on the whole as many people give them credit for.  For one thing, even the most aggressive of snakes will typically avoid attacking humans, if they can help it, unless they feel cornered, and even then they’ll usually give warning before striking.  On top of that, around 80% of snakes aren’t significantly harmful to humans, even if they do bite you. Even those that are deadly, most will occasionally not inject venom into you when they strike, simply wanting you to leave.  The exact percentage of “dry bites” varies from venomous snake to venomous snake, but, for instance, around 50% of Coral Snake bites are dry bites, delivering no venom.

In fact, only 9-15 people per year in the U.S. die from snake bites out of about 8000 bites from venomous snakes per year.  This means you are about nine times more likely to die from being struck by lightning than die from being bitten by a snake in the United States.  Even in Australia where seemingly everything in nature seems capable of killing humans and where 7 out of the world’s 10 deadliest snakes live, there is only about 1 death by a snake bite per year.  In both the U.S. and Australia, this is less than are killed annually by bee and wasp stings.

Then again, there are such snakes as the Black Mamba, residing in certain parts of Africa, that you’ll want to run screaming like a little girl from if you ever encounter one. The Black Mamba’s kill rate after a strike is 100% unless large amounts of anti-venom (typically 10-12 vials) are administered very shortly after being bitten.  Given how quickly its venom can kill (as quickly as 10 minutes, though sometimes it takes a few hours, depending on how much is injected; the average time until death after a bite is around 30-60 minutes), around 95% of people still die from Black Mamba bites usually due to being unable to get the anti-venom administered in time.  One single strike from a Black Mamba will deliver around 100-400 mg of venom and only 10-15 mg is needed to kill a human.

They also usually won’t just strike once, but will continually strike whatever is threatening them as much as they safely can before it stops moving.  If it’s a large, dangerous animal they’re striking, they may only strike a few times in quick succession, then may or may not follow the animal until it dies. If they do follow, they usually will continue to strike only when they see safe opportunities, being less fearless than when they’re cornered.  As you might expect from this, Black Mamba’s are at the top of the food chain, outside of humans.

What’s particularly frightening about this snake, apart from being amazingly deadly and 8-14 feet long, is that the Black Mamba can also move as fast as 14 mph, with an average top speed in the range of 10 mph to 12 mph.  In either case, this makes them the fastest snake in the world.  They can also maintain speeds of around 6-7 mph for long periods.

If all this wasn’t bad enough, the Black Mamba is considered to be the most aggressive snake in the world.  However, it should be noted that even having the reputation of being extremely aggressive, it usually only attacks humans when it feels cornered or when a female is protecting her eggs.  When it does feel like fighting, it’s incredibly fearsome.  Because of its size, ground speed, and agility; how quickly it can strike; how fearless it can appear to be; and how deadly its venom is (I for one welcome our new Black Mamba overlords), it generally takes a group of people working together to kill one and even then it’s a dangerous endeavor. So you’ll not want to encounter one of these alone, whether on land or in the water.  In both cases, best to have someone with you that you are faster than!

Bonus Snake Facts:

• A simple way to determine if a snake that has bitten you is venomous or not is that usually venomous snakes will leave two fairly deep puncture wounds after they’ve struck.  Nonvenomous snakes, on the other hand, will generally leave small, very shallow punctures in a horseshoe shape.
• What to do when bitten by a venomous snake:
  • If you get bitten by a venomous snake, you should immediately call for emergency aid (no-brainer). You should also try to keep your movements to a minimum and stay completely calm. The more you get your heart a-pumping, the quicker the venom will spread through your body. As such, if possible after calling for aid, you should lie down and relax. If the bite is on a limb, you should make sure that limb is lower than the rest of your body as you relax.
  • If you can’t just sit around and wait for aid to arrive (such as if you need to hike out of somewhere), it is generally recommended you first calm yourself for several minutes, slowing your heart rate as much as possible, then walk at a very leisurely pace to a place where you can get aid.  You basically want to avoid exerting yourself at all, which will cause the venom to spread throughout your body much more quickly.
  • Another thing you should do immediately is take off any bracelets, shoes, rings, and similar items you are wearing near the affected area. It’s going to swell up, sometimes severely, so you want to make sure you can get those off before this happens. Otherwise, it’s going to be difficult and cause you a lot of pain, particularly in cases like rings or bracelets which will not only be painful, but likely have to be cut off.
  • If you’ve got any on hand, while you’re relaxing or calming yourself before hiking out of someplace, wash the bite with soap and water.
  • DO NOT cut the bitten area and try to suck out the venom.  You’ll not be able to suck out much of the venom anyways and further damaging tissue in the area will allow the venom that remains to further diffuse in your body.  If you want to try to suck out the venom without cutting the area, feel free, but don’t expect it to do much.  There are suctioning devices included in snakebite kits, but, again, don’t expect this to do too much.
  • If the bite is on a limb, you might be tempted to apply a tourniquet… don’t. This can ultimately result in you losing that limb and in extreme cases, where the tourniquet has been left on long enough, this can even kill you as the now toxic (due to oxygen deprivation) blood gets released into the rest of your body if the limb isn’t amputated.  You can read more about the risks of applying a tourniquet to a limb here: What Causes Arms, Legs, and Feet to Fall Asleep
  • Instead of a tourniquet, you should apply a slightly constricting 2-3 inch band above the area where the bite is.  When doing this,  use a soft material, such as a strip of cloth from a shirt.  Tighten it around the limb about the same tightness you feel when a nurse who is drawing blood from you wraps an elastic band around your arm.  Basically, you don’t want to cut off blood flow at all, but applying a small amount of constriction will reduce the flow of lymphatic fluids, which is good in this case.  As your limb swells from the bite, you’ll find the band you put on will get tighter.  Adjust the band as necessary to keep it loose enough to not block blood flow.  One other thing to note here is that you shouldn’t place the band directly above or below a joint.  So if you were bitten on the hand, don’t put the band right next to your wrist, put it further up your forearm.  Similarly, don’t put it directly above or below your knee or your elbow.
  • You may also be tempted to apply ice packs to the area.  Surprisingly, this has been very recently shown to make the effects of the snake bite worse, so don’t do it.
• Somewhat oddly, snakes have long been associated with medicine and healing.  Examples of this can be seen in Jewish history, as well as in Ancient Greece and other cultures.  For instance, in Ancient Greece, the god of healing and medicine, Asklepios had servants who were snakes and if a snake touched you with their tongue, supposedly it helped you heal.  Because of this, snakes were often used by physicians in this way.
• The Black Mamba doesn’t get its name from actually being black on the outside, it usually has more of a grey, brown, or olive color.  The name comes from the fact that its mouth is black, as you can see in the picture to the right.
• When a Black Mamba male encounters a female during mating season, he will start off by flicking his tongue over her entire body, inspecting it thoroughly.
• Stay away from abandoned termite mounds in Africa.  This is a favorite place for female Black Mambas to lay eggs.  They are extremely aggressive as they guard their eggs over a couple month period and as noted, very fast.  Further, when the snakes are hatched, they’re just as venomous as their adult counterparts, so you’ll not want to encounter one of these either.
• It’s a good thing Coral snakes tend to run from humans and even when they bite only 50% of the time will release venom because, particularly with North American Coral Snakes, they are fairly deadly when they do inject venom.  Further, you’ll be hard pressed to find Coral Snake anti-venom in the United States because there are so few bites (15-ish) each year that keeping a stock of it on hand isn’t anywhere close to cost effective and current stocks of this anti-venom in the U.S. expired in 2010, with no plans by major U.S. pharmaceutical companies to produce more.
• Water snakes often like to sun on tree branches overhanging water.  When they detect movement below the branch, they will drop and attack.  While they usually don’t like to attack humans, sometimes they will drop the second they perceive movement below the branch, before realizing it’s people they’re about to attack.  As such, when you’re in a boat on the water, particularly if it’s a canoe or something similarly small, you should avoid traveling under overhanging branches.  Being stuck in a small boat with a potentially venomous snake who now will feel cornered isn’t a recipe for a good time.
• Certain snakes will act like they’re dead when they encounter potential predators, such as the Spitting Cobra.  This snake will even let their tongue hang out of their open mouth, as they lay rolled over on the ground.  Further, they’ll excrete an extremely smelly substance from their anal gland which will make them smell rotten and awful.  Most predators, thus, will leave this apparently rotting thing alone.  If they’re forced to fight, Spitting Cobras can spray venom up to 3 feet away from itself.  They’ll usually aim for the eyes when they spit, in order to try to blind their opponent.  If you get close enough, they’ll also strike and inject venom in a more normal fashion for snakes.
• Another interesting kind of snake is the Chrysopelea, also known as the “flying snake”.  This snake actually can fly, after a fashion.  It has the ability to use scales on its belly to climb straight up trees.  Once it’s high enough, it will dangle from a tree branch.  It then selects a target and bends itself into a J.  Finally, it flings itself away from the tree towards its target and sucks in its stomach and flares out its ribs, creating a sort of flying torpedo, with lateral undulation (not unlike the way snakes move through water). Combined with the way they shape their body, this lateral undulation actually creates lift, allowing them to glide.   They are capable of making flights as long as 100 meters doing this.
• Rattlesnakes are able to make a rattling noise because their tails are comprised of 6-10 layers of scales.  When these layers of scales are shaken, they rattle.
• The Calabar Ground Boa has an equally interesting trait.  Their tail actually looks very similar to their head.  When they coil up, they hide their real head and leave their fake “head” on their tail exposed.  When a predator tries to grab or bite the fake head or is otherwise paying close attention to the fake head, they strike with their real head.
• Another interesting trait in a snake is found in the Dasypeltis Scabra (also called an “Egg Eater”).  This snake has special vertebrae that first puncture the egg (after it’s been swallowed and begins passing through the snake) and then other bones in the vertebral column hold the egg so that it doesn’t go too far into the snake.  Finally, more specialized vertebrae crush the egg.   Once this is accomplished, rather than processing the shell, the snake regurgitates it.
• The word snake comes from the Old English “snaca”, which in turn derives from the Proto-Indo-European word “(s)nēg-o”, meaning “to crawl” or “to creep”.  This is also where we get the word “sneak”.
• Contrary to popular belief, snake skin on a living snake isn’t slimy or oily.  It’s actually has a dry texture and parts of their bodies are often fairly smooth.
• There is no such thing as a poisonous snake.  Snake venom is not poison, it is venom.  What’s the difference between poison and venom you say?  The difference is in the delivery. Poison must be inhaled, ingested, or delivered via touch, while venom is injected into a wound.  This may seem overly pedantic, but it should be noted that usually venom isn’t poisonous (meaning it generally won’t hurt you too much or at all if delivered in a different fashion than injecting, even if you swallow it).
• While in most places, the annual death rate from snake bites is fairly low, in India, around 50,000 people per year are killed by snake bites (out of about 250,000 bites annually).  As you might infer from this, a good percentage of Indians don’t have access to anti-venom. Given that there are more homeless people in India than the entire population of the United States and that it is this group that is likely suffering the most bites, this isn’t surprising.
• The fastest running speed ever recorded for a human is 27.79 mph by Jamaican sprinter Usain Bolt.  He maintained this speed for a short burst between the 60 meter and 80 meter mark of a 100 meter sprint.  He need not fear the Black Mamba too much.
• Cheetahs are capable of reaching speeds around 60-80 mph.
• American quarter horses are surprisingly fast, able to achieve top speeds of up to around 50-60 mph.