For the most part, these adult fireflies don't get eaten because like their juveniles they can manufacture toxins that are repellent to birds and other insectivores, but somewhere along the line, one particular group of fireflies somehow lost the metabolic machinery needed to make their own protective toxins.
大部分情况下，成年萤火虫不会被吃掉， 因为像它们小时候一样， 它们可以制造毒素， 让鸟儿和其他食虫动物躲开它们。 但在历史中的某一处， 萤火虫中的某一族， 莫名其妙地就失去了这种代谢机制， 但它们又必须制造自己的防卫毒素。