Venomous vs. Poisonous – What’s the Difference?

If you are a biologist studying indigenous wildlife in a remote tropical location, the difference between the words venomous and poisonous can be the difference between a brilliant new discovery and a slow, agonizing death.

Each of these words describes organisms which produce toxins. However, strictly speaking, most organisms that are poisonous are not venomous, and most organisms that are venomous are not poisonous.

Continue reading to discover the differences between these words.

What is the Difference Between Venomous and Poisonous?

In this post, I will compare venomous vs. poisonous. I will use each of these words in a set of example sentences, so you can see them in context.

Then, at the end, I will show you a mnemonic device to help you remember whether something is venomous or poisonous.

When to Use Venomous

venomous versus poisonousWhat does venomous mean? Venomous is an adjective. It describes an organism that injects toxins into its victims, usually by stinging or biting.

Here are some examples,

  • The venomous scorpion kills its prey by grasping it in its pincers and using its powerful stinger to inject its venom.
  • Philomena’s house is full of venomous spiders, and she needs to call an exterminator before I will go there.
  • I found a venomous snake in my garden, but I let it live in the hope that it would kill the rodents that eat my vegetables.
  • A venomous Indian cobra is recuperating at the Bronx Zoo after it was discovered cold and dehydrated aboard a ship that docked this week in Newark, N.J., zoo officials said. –The Wall Street Journal

Snakes, scorpions, spiders, etc., are all examples of animals that are venomous—not poisonous.

When to Use Poisonous

Definition of poisonous definition of venomous definitionWhat does poisonous mean? Poisonous is also an adjective. It describes an organism which delivers toxins when touched or eaten, but not by injecting its victims with toxins. I have included a few examples below.

  • Jermaine ate a poisonous frog, and died a painful death.
  • Do not eat the berries that grow along the garden path; they are poisonous and will make you sick.
  • If you touch the poisonous leaves of some ivy plants, you will get a painful rash.
  • Remembering the rapid effects of eating poisonous mushrooms on a woman, another character says, “They were measuring her for her coffin before she sat up and asked for a glass of water.” –The New York Times

As you can see, there is a clear different between poisonous and venomous. Poison ivy, for instance, is poisonous, but it isn’t venomous.

And the word poisonous describes other substances, not just plants and animals. Bleach is poisonous. It is harmful when swallowed and inhaled, and it can also damage the eyes and skin.

Poisonous or Venomous? Remember the Difference

Define poisonous and define venomousHere is a helpful trick to remember poisonous vs. venomous.

Venomous only describes organisms that deliver toxins via injection. Organisms that deliver toxins through other methods, like simple contact or being eaten, are poisonous. Other substances, like chemical cleaners and substances leached by certain plastics, can be poisonous as well.

To remember that venomous refers to animals which inject toxin, remember that the words venomous and viper each begin with the letter V.


Is it venomous or poisonous? The adjectives venomous and poisonous each describe organisms that produce toxins.

  • If the organism injects toxins, by biting or stinging, it is venomous.
  • If it delivers toxins via touch or other routes, it is poisonous.

Many other substances, like household cleaners and food additives, are also poisonous but not venomous.

Since the words venomous and viper each begin with the letter V, and vipers are venomous, you can easily remember that venomous creatures inject toxins into their enemies and prey.

In summary,

  • Venomous refers to organisms that sting or bite.
  • Poisonous refers to organisms that still produce toxins, but do not sting or bite.