The terms ‘venomous’ and ‘poisonous’ are often used interchangeably, but they’re two very different things. To start out with, both are toxins, substances created by living things that can do harm to other living things. If a toxin is actively injected into you by a bite or a sting, that organism is venomous. If you absorb the toxin like by eating it, breathing it in, or by rubbing it on your skin, then that organism is poisonous.
Graslie also takes a closer look at how some reptiles and amphibians have evolved these toxins and how they’re used in a sort of evolutionary arms race—”an ever escalating race or competition.” Featured creatures include the false water cobra, the cane toad, the shingleback skink, and more.