sang piao xiao or sangpiaoxiao (chinese: 桑螵蛸, sometimes called mantis cradle or ootheca mantidis in english) is a pinyin transliteration referring to the oothecae, or egg case, of the praying mantis as an ingredient in traditional chinese medicine. a formula based on this ingredient is known as "sang piao xiao san" (or "sangpiaoxiao san") and is also known as "mantis formula" in english. the formula may also be sold as a pill (""sang piao xiao wan"").