Q&A: Venomous vs poisonous

Each week here at the Australian Writers’ Centre, we dissect and discuss, contort and retort, ask and gasp at the English language and all its rules, regulations and ridiculousness. It’s a celebration of language, masquerading as a passive-aggressive whinge about words and weirdness. This week, name your poison…

Q: Hi AWC, what’s the difference between “venomous” and “poisonous”?

A: Good question. They’re both bad.

Q: Yeah clearly. I’m thinking in particular about things like snakes and spiders – I’m sure sometimes they’re called venomous and other times poisonous. Is there a distinction?

A: The two words are often used interchangeably, but scientifically there is a big difference.

Q: Which is?

A: How the toxins reach you.

Q: Oh, big hats, like to say “yee ha!” a lot and eat ribs?

A: No, you’re thinking of Texans.

Q: Ah yes, oops.

A: Toxins are “organic poisons” and the difference between “venomous” and “poisonous” is simply how they’re delivered.

Q: Like a toxin taxi service? A “toxi” if you will?

A: We will not.

Q: Ahem, okay, sorry. Carry on.

A: Let’s begin with “venomous”. In zoology circles, “venom” is a toxic fluid that is delivered from naturally evolved glands via things like fangs or a stinger into your bloodstream. So to be “venomous”, the animal actively injects you with venom by biting or stinging.

Q: So that’s most snakes, spiders, bees?

A: Yep. Others include box jellyfish, stingrays (RIP Steve Irwin), catfish, some lizards, platypus, vampire bats and even a particular type of shrew.

Q: I thought shrews were tame?

A: Only in Shakespeare plays.

Q: Ohhh, that reminds me. What Shakespeare play is about a little pig?

A: Umm, Hamlet?

Q: No, none of them are! Hahaha. Shakespeare wrote NO plays about pigs! I can’t believe you thought Hamlet was about a pig!

A: Can we continue?

Q: Yes, of course. So, what’s the go with “poisonous” then?

A: Think of it as the passive-aggressive sibling of the bitey, stabby “venomous”. If something is “poisonous” it doesn’t need to create a wound and inject you with anything. Instead, it just sneakily releases its toxins if you’re silly enough to touch or swallow it.

Q: Examples?

A: A cane toad isn’t poisonous unless you eat or lick it. Poison ivy just needs to come into contact with your skin and it will result in a rash. And of course certain chemicals are poisonous if swallowed.

Q: Brussels sprouts too.

A: They’re not poisonous. You just don’t like them. That’s not the same thing.

Q: Okay fine.

A: But yeah, quite a few birds are poisonous if eaten, along with many other frogs, insects and plants.

Q: So, if a snake bites you, it’s not technically a “poisonous snake”?

A: That’s right. It’s a “venomous snake” and you’ll be wanting some anti-venom. Of course, it’s unlikely anyone will ever stop to debate this with you if you told them you’d been bitten by a poisonous snake. 

Q: True. What about a boa constrictor then?

A: Well, it doesn’t bite, but can crush you, so let’s just call that one a “deadly snake” shall we? There are also a few truly poisonous snakes that you cannot eat.

Q: Got it.

A: And then of course there’s the double-whammy blue-ringed octopus. It’s both venomous via its beak AND poisonous if you eat it.

Q: I wonder if those blue rings are related to the zoology circles you were talking about earlier?

A: Huh?

Q: Never mind. So, here’s a question. What if I took a vial of venom and swallowed it. What would happen?

A: Wow, that’s a very good question. Because venom typically needs to enter the bloodstream to take effect (hence the piercing of skin via a bite or sting), then providing you had no cuts, your stomach acids would probably deal with it and you’d be okay. We wouldn’t recommend trying it though.

Q: Fair enough. So, to recap, anything that bites or stings you is “venomous” and the rest of the stuff is “poisonous” – including things you swallow or touch.

A: Yes. But remember, this is in the natural world. If you’re talking more about a “poisonous personality” or “venomous intentions”, well all bets are off and you can choose whichever you want!

Q: Good to know. Now, if you’ll excuse me, my toxi is waiting…

Do you have a question you’d like us to explore? Email it to us today!