Many animals use poisonous secretions to protect themselves from predators. But poisons are complex chemicals and can take a lot of energy to make. Why invest in them, when you can steal someone else's?
Poison thieves are well-known in the animal kingdom. Many species of brightly coloured poison arrow frogs acquire their poisons from beetles, while some sea slugs make a living by hunting for jellyfish, transporting their stinging cells into their own limbs. Now, another species joins this guild of thieves - the tiger keelback snake, Rhabdophis tigrinis (image right, by Deborah Hutchinson).
The tiger keelback lives in Japan and uses its poisons for defence rather than attack. When threatened, it angles two glands on the back of its neck towards the predator. The fluid that oozes from these 'nuchal glands' contains chemicals called bufadienolides, that irritate airways and affect heart muscle. But the glands themselves lack any of ...