The tiger keelback is shy, so it would be rare to be attacked by one, but they sometimes do, and they do need to survive. And in order to survive, a snake must have a good form of defense. And the tiger keelback has a very interesting form of defense. In addition to having ordinary venomous snake fangs, they have another trick up their sleeve. Like the poison dart frog and sea slug, the tiger keelback doesn't bother to produce its own venom - rather, it gets its deadly venom from the toads it eats as part of its normal diet. When the tiger keelback feels even the tiniest bit threatened, it'll angle the two little glands on the back of its neck and use it against the predator, the one who seems a threat to the snake. The liquid, or rather, "fluid," that exits the snake's nuchal glands contains something called bufadienolides, that irritate airways and affect heart muscle. 