Is Venom the Same as Poison?

Step 1 of 5

Venom needs a delivery system.

A venomous animal has hardware: fangs, a sting, a spine or a barb, plus a gland to make the venom and a muscle to squeeze it down the tube.

Step 2 of 5

Poison just sits there.

A poisonous animal has no hardware. Its defence is in its skin or its flesh, and it only works on something that has already bitten it — which is why poisonous animals are so often brightly coloured.

Step 3 of 5

Most venom is for eating, not defence.

A spider or a snake mostly uses venom to stop a meal escaping and to start digesting it. Defending itself is the second job, and many would rather retreat than spend the venom.

Step 4 of 5

It is a mixture, not one thing.

Venom is dozens of different chemicals at once. Some jam the nerves, some break down flesh, some stop blood clotting — which is why one antidote does not work for another animal.

Step 5 of 5

Some of it ends up as medicine.

A chemical good at jamming one exact thing in the body is useful if that is the thing you want jammed. Blood-pressure drugs, painkillers and clot treatments have all come out of venom.

A pufferfish is poisonous, not venomous. A jellyfish is venomous — the stinging cells inject. A poison dart frog is, as the name says, poisonous.