Biology's Most Amazing Lists: Lethal Venom and Deadly Chemicals

The natural world is full of creatures with amazing abilities and specializations, including the ability to produce venom and poisons. Below is a list of the deadliest venom and poisons found in nature.

Here's another "." This time, we explore the lethal world of venom.


There are probably hundreds of animals out there that can kill you, but this is a list of five extremely venomous species, according to Discovery Magazine.

It is important to realize that a poisonous species produces poison as a defense mechanism, not looking to harm others, but to protect themselves.

Venomous species, on the other hand, inject venom through bites and stings to subdue and ultimately eat prey species.


  • The poison dart frog: This tiny, poisonous frog is found in the rainforests of Central and South America, according to the Smithsonian National Zoological Park. The frog's brilliant colors serve as a warning for any would-be predators trying to make a meal out of one. According to Discovery Magazine, only two micrograms (a millionth of a gram) of its poison is all that is needed to kill a human. In case you were wondering, the ink in a single period on a piece of paper weighs six micrograms. This frog got its name from the fact that indigenous peoples once used the venom secreted from the frog's skin to coat their arrows with venom.

  • The stonefish: This creature gets the award of the most poisonous fish. It can be found in Indo-Pacific and northern Australian waters. The toxin is stored in large spines on the back of the fish that are used to inject venom into predators. Like the poison dart frog, this animal is poisonous, but not venomous; it doesn't use its venom to obtain food. According to Oracle's ThinkQuest site, the sting causes excruciating pain, followed by swelling and death of the surrounding tissue. If left untreated, the sting can be fatal.

  • The Brazilian wandering spider: If you are afraid of spiders, things are about to get worse. The Brazilian wandering spider is the most poisonous spider known to man, according to The Guinness Book of World Records. These spiders are found throughout South America and get their name from the fact that they roam on the ground, not on a web. The spider's venom works as a neurotoxin by blocking synaptic connections in the brain, leading to loss of muscle control, breathing problems and eventually death. Remember, this animal is considered venomous because it uses its venom to kill prey.

  • The inland taipan: This is considered the most poisonous snake in the world by a number of sources, including Discovery Magazine. This venomous snake is found in the continent of Australia. According to the Clinical Toxinology Resources site, the inland taipan's venom consists of several toxins. The venom contains neurotoxins, which work to disable muscle control and breathing; procoagulants, which stop blood from clotting, renal toxins, which affect the kidneys; and myotoxins, which cause muscle damage. This is not a snake you wanna get bit by.

  • The Australian box jellyfish: This species is widely claimed to be the most venomous animal in the world. It is found in waters surrounding Asia and Australia, and it delivers its venom with extremely long tentacles lined with special stinging cells called nematocysts. The box jellyfish's venom affects the heart, nerves and skin. According to Outback Australia Travel Guide, approximately six feet of its tentacle making contact with the skin is enough to cause cardiac arrest within minutes. If stung while swimming, it is very uncommon to make it back to shore alive.

Plants, fungi and bacteria:
I know what you're thinking: I have to look out for , too?

Unfortunately, the answer is yes, and some are common to this area!

This list was compiled from Discovery Channel's How Stuff Works.

  • The castor bean: This plant is commonly grown in gardens around the world for decoration and for castor bean oil. The oil is widely used for food additives and candy production. The seed coat, however, contains a poison called ricin. According to How Stuff Works, three seeds are enough to kill a child. The poison affects the kidneys and causes circulation failure.

  • Deadly nightshade: This species of plant is cultivated in the United States. The poison atropine is found in its stems, leaves, berries and roots. As few as two berries can kill a child, while approximately 15 or so can kill an adult. The poison works as a neurotoxin to shut down involuntary muscles involved in circulation and breathing.

  • Rosary pea: The berries of this plant are used to make rosary beads in other parts of the world. The plant is native to Indonesia, but has been found in some of the southern states of the U.S. The berry is perfectly safe as long as the seed coat isn't broken. If the coat is broken and the poison abrin is absorbed into the body, protein synthesis in the body can be shut down—leading to death. Only three micrograms are required to kill an adult.

  • Water hemlock: The water hemlock's white roots are sometimes mistaken for parsnips. The plant poison cicutoxin is most concentrated in the roots. If ingested, the poison causes violent convulsions, nausea, vomiting, cramps and muscle tremors. Death is a very possible outcome, but those who survive usually suffer from amnesia.

  • Oleander: This plant is considered to be the most poisonous in the world. The two most prevalent poisons, oleandrin and neriine, are so potent that one can be poisoned from eating the honey produced by bees that got nectar from the oleander's flowers. Oleander is found mostly in Europe, but also grows in the United States. One leaf of this plant can kill a child, and symptoms usually include diarrhea, vomiting, stomach pain, drowsiness, dizziness and irregular heartbeat.

  • The destroying angel: This mushroom is extremely poisonous and usually fatal if ingested. The mushrooms can be found all across North America and in Europe. The toxin, amanitin, can easily be fatal if about half a mushroom cap is eaten. Symptoms include vomiting, cramps, delirium, convulsions and diarrhea. The venom also targets the tissues of the liver and kidney, which is what causes death.

  • Clostridium botulinum: I saved the most potent poison for last. This species of bacteria produces the most potent toxin known to man. The bacteria are found in almost all soil environments and are easily killed while cooking vegetables. Their spores, however, can withstand massive amounts of heat and can re-germinate in your body. The toxin, botulinum, causes the disease known as botulism. One teaspoon of botulinum can kill 1.2 billion people! According to MedicineNet.com, symptoms of botulism include double vision, blurred vision, drooping eyelids, slurred speech, difficulty swallowing, dry mouth, muscle weakness and constipation. These are all signs of muscle failure and paralysis. Paralysis is caused by the fact that the toxin affects the nervous systems, and the toxin could ultimately cause death by asphyxiation.

I encourage everyone to check out all embedded links to see what these plants and animals look like if you ever come in contact with them.

We in the northeastern part of the country really only need to worry about the plant species, but try to imagine what it must be like to swim in Australia near the box jellyfish.

Think about it.


Please be sure to check out a very special video article of Practical Science, featuring an exclusive interview with Dr. Clint Springer, professor of biology at St. Joseph's University, about the topic of global climate change and its effects on us and our enviornment.

Lisa Dalantinow May 31, 2011 at 01:44 AM
Wow didn't know there were so many toxins in our enviorement. I was in the rainforest in Costa Rica and the person who was showing us the rainforest told all of us to stop and don't move because he had spotted this tiny frog and told everyone not to touch it if they didn't want to die. As you have written we all need to watch the food and different places that could bring such harm to us. Thank you again for a very well written article, and as usual you bring such interest to all the topics you discuss. Lisa
Heather Greenleaf May 31, 2011 at 01:58 AM
Great, but scary, article! Interesting point about the difference between poisonous and venomous.
Philip Freda May 31, 2011 at 05:00 PM
Thanks Heather, glad you liked it. I still have trouble separating the two terms.
Philip Freda May 31, 2011 at 05:01 PM
Thank you very much. We actually have poison dart frogs in one of our labs. The interesting thing is, poison dart frogs do not produce venom in captivity and no one really has a good explanation why.


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