Boreidae, commonly called snow scorpionflies, or in the British Isles, snow fleas (no relation to the snow flea Hypogastrura nivicola) are a very small family of scorpionflies, containing only around 30 species, all of which are boreal or high-altitude species in the Northern Hemisphere. Recent research indicates the boreids might be more closely related to fleas than to other scorpionflies, which would render the order Mecoptera paraphyletic if the order Siphonaptera is excluded from it.