From Our 2010 Archives

Research Reveals Secret of Spitting Cobras' Aim

FRIDAY, May 14 (HealthDay News) -- Spitting cobras spray venom at the eyes of creatures they consider aggressors, and their aim is often perfect -- even when the eyes may move between spit and splat -- and researchers now know how they do it.

A new study, by a man who allowed spitting cobras to take aim at him while he was protected, suggests that the snakes not only track their target -- the eyes -- but figure out where they'll be in a matter of milliseconds.

Bruce Young, of the University of Massachusetts at Lowell, discovered that cobras do their tracking by wiggling their heads just before letting loose with the venom. Wearing goggles and a visor loaded with accelerometers to track his own head movements, he provoked the cobras while his colleagues filmed the snakes' movements. When Young suddenly jerked his head, he and his colleagues found the snakes' heads quickly turned in the same direction that his eyes were moving.

First, it seems, the cobras follow their victims in real time -- where they are right this very instant -- then they estimate where the victim's eyes will be in 200 milliseconds, when they actually get hit by the projectile spit.

It took more than 100 spits at a laboratory in Germany to figure out what a cobra is up to when it spits so accurately. "Not only does it speed up, but it predicts where I am going to be and then it patterns its venom in that area," Young said in a news release from The Company of Biologists.

The story is published in the May 14 online edition of the Journal of Experimental Biology.

-- Randy Dotinga

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SOURCE: The Company of Biologists, news release, May 14, 2010