Woolly aphids (subfamily: Eriosomatinae) are sucking insects that live on plant sap and produce a filamentous waxy white covering which resembles cotton or wool. The adults are winged and move to new locations where they lay egg masses. The nymphs often form large cottony masses on twigs, for protection from predators. In flight they have been described as looking like "flying mice." Other nicknames include "angel flies", “cotton fairies”, "fluff bugs", "fairy flies", "ash bugs", "snow bugs", "fluffer fairies", "poodle flies", and "fluffy gnats".