Steinflies
Steinflies is a term that can refer to several different things. Most commonly, it is a German word literally translating to "stone flies." In entomology, this refers to the order Plecoptera, which are aquatic insects known for their two tails and delicate wings. They are an important indicator species for water quality, as their larvae are sensitive to pollution.
In a non-entomological context, Steinflies might be a surname, or it could refer to a fictional entity