Several species of newts and frogs produce the toxin, known as tetrodotoxin, that is more lethal than cyanide. The six snake species—including three kinds of North American garter snakes—have independently developed a nearly identical molecular mechanism for resisting the toxin, according to a study published in the Proceedings of the National Academy of Sciences. Tetrodotoxin attacks an organism by binding to sodium channels in the body’s cells, which interrupts electrical impulses in the muscles. Normally, this quickly results in paralysis and the death of any animal that ingests it. The six snake species studied, however, have independently evolved an adaptation over millions of years that inhibits the toxin from binding to the sodium channels. What’s interesting to the researchers is that the mechanism for resistance is essentially the same in all six species, regardless of where they live or the kind of prey they eat.