Some vipers are the sprinters of snakes. Researchers compared 36 venomous snakes from three families. Vipers wielded the fastest attacks. Some members of one of the other families could give slower vipers stiff competition. Scientists Say: Venomous Scientists shared the new findings October 23 in the Journal of Experimental Biology. The quickest snakes tend to be ambush predators. The true speed demon: terciopelo (Bothrops asper). This pit viper, also known as the fer-de-lance, feeds on birds and mammals. It can be found slithering from eastern Mexico to northern South America. To catch birds and rodents, its attack had an average strike velocity of 3.5 meters per second (11.5 feet per second). Here’s a closeup of the fer-de-lance (Bothrops asper) — the venomous snake with the fastest strike, as measured in the new study. Though dangerous, with a bite that can lead to death, this pit viper has evolved to be a useful member of its healthy tropical ecosystem. Mammals, key prey for these big snakes, typically take only 60 to 400 milliseconds to react and …