To take the zap out of a school of electric eels, fishermen in 17th century South America sent teams of horses into the water as bait, scooping up the eels after they had exhausted themselves in the attack. According to famed naturalist Alexander von Humboldt, the eels would leap out of the water to shock the frightened - but mostly unharmed - horses. Until now, no one else had recorded evidence of such behavior, and many scientists were skeptical of Von Humboldt’s account. A new study shows that not only do the animals leap from the water to attack their prey, but they also increase their voltage as they leap (see video below). The jumping behavior was first observed by accident: As scientists were studying the eels in an unrelated exper ...