The little insects share the food while eating in groups. In the past one could often see a dozen or so of the bugs devouring a snail at water's edge. "This avoids leaving behind rotting meat which could affect water quality," says Yang Ping-shih, a specialist in insect damage to plants at National Taiwan University.
小蟲會成群分食，過去水邊就常可見十幾隻小蟲共食一隻蝸牛，「如此可以避免殘渣剩肉，影響水質」，從事昆蟲研究的台大植物病蟲害系系主任楊平世說，幼螢是水域生態的捕食者。