A painkiller as powerful as morphine, but without most of the side-effects, has been found in the deadly venom of the black mamba, say French scientists.
The predator, which uses neurotoxins to paralyse and kill small animals, is one of the fastest and most dangerous snakes in Africa. However, tests on mice, reported in the journal Nature, showed its venom also contained a potent painkiller.
They admit to being completely baffled about why the mamba would produce it. The researchers looked at venom from 50 species before they found the black mamba's pain-killing proteins - called mambalgins.
Dr Eric Lingueglia, from the Institute of Molecular and Cellular Pharmacology near Nice, told the BBC: "When it was tested in mice, the analgesia was as strong as morphine, but you don't have most of the side-effects."