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– A new study has revealed a big surprise about electric eels: they hunt in groups. Prior to the study published in Ecology and Evolution, scientists thought the creatures hunted, zapped and then ate only fish, the BBC reports. But in a Brazilian river in the Amazon, researchers for the first time documented a pack of Volta’s electric eels (technically knife fish) that work together to round up and kill small fish, according to Live Science. The eels gather in groups of about 100, then surround tetrafish and float to shallow waters. There, smaller groups of eels come closer and zap the tetra, sometimes with enough force to make them fly out of the water. The demobilized tetra are then easy to pick. While it’s common for mammals to hunt together, this is rare in fish, CNET explains. The number of fish species that do this is estimated to be around 10.
“This is an extraordinary discovery,” said senior study author C. David de Santana, per Smithsonian Magazine. “Nothing like this has ever been documented in electric eel.” Volta’s electric eels grow to about 8 feet long and can deliver a shock of 860 volts, the most powerful of all creatures on Earth. If 10 were zapping at the same time, it would be enough to power 100 light bulbs, Santana says. And yes, he zapped himself and describes it as strong enough to cause numbness in his arms. “It’s a really strong discharge, but the duration is very short,” he says. Researchers have documented the hunting strategy several times on Brazil’s Iriri River, although they are unsure how widespread it is among eels elsewhere. They have started a citizen science project to gather more information. (Read more stories about electric eels.)