The Difference Between Venomous and Poisonous

Bees, spiders, and snakes all have reputations for making us sick with their bites.

Is it because they're all poisonous? Would you believe that almost none of the bees, spiders, or snakes in North America are poisonous? It's true.

Venomous, well that's a different story.

First of all, we can call all of them toxic. Toxin is the official term for a naturally occurring substance that causes your body to behave badly. There's no official difference between poisons and venom as far as chemical compounds go. Toxins come in all sorts of different chemicals and can be created in more ways than I've ever counted.

The difference between whether a critter is venomous or poisonous has to do with how the toxin is delivered to us. You could say it's not the present itself, but the thought that counts when it comes to toxic exposures.

Venom extraction
Rithwik photography / Getty Images

Passive Poisons

Poisons are passively applied. They get into your system through some act of yours — you inhale, ingest, or absorb it through touch. Most toxic plants are poisonous. Toadstools, for instance, are pretty harmless unless you eat them. Poison ivy is, well, poisonous if you touch it.

It's not just plants but animals can also be poisonous. There are many species of caterpillar, for example, that are poisonous to touch. They don't have to do anything to you, just come in contact with your bare skin. Those little, colorful poisonous frogs from the tropical rain forests don't inject anything into anyone. They don't bite, either. They just ooze poison until you come along and pick them up.

Venom Requires a Verb

Indeed, there is a verb for getting venom. It's called being envenomated.

Venom is actively applied. Bees, wasps, spiders, and snakes, must inject their toxins through biting or stinging. Or, in the case of spitting cobras, squirt it at you. The toxin itself might only need to come in contact with bare skin to do its damage, but the difference is in the delivery. Venom requires a verb, an action for those of you who don’t remember English class, to reach its intended victim.

Does It Really Matter?

The truth is, whether we're talking about a venom or a poison, they're all toxic and they all make you sick. In fact, one could argue that since there isn’t really a difference, they’re all poisons.

What we call venom or poison has to do with colloquial usage. Let’s face it, more people come to the internet looking for food poisoning than foodborne illness, even though in the scientific community the latter is preferred. For the record, however, many of the signs and symptoms of foodborne illness come from toxins created by the organisms growing on the food. Since those toxins are passively transferred to you when you eat the food, it is, strictly speaking, poisonous.

This isn’t an area where the word police should get too fired up. At the end of the encounter aren’t you still just as sick?

By Rod Brouhard, EMT-P
Rod Brouhard is an emergency medical technician paramedic (EMT-P), journalist, educator, and advocate for emergency medical service providers and patients.