A species of flower fly from Costa Rica, Eristalis gatesi.

(idiomatic) To pilot an aircraft without the aid of instruments and without a flight plan, using only instinct, visual observation, and practical judgment.

(simile) To be frantic, harried or restless

Alternative form of when pigs fly

(idiomatic) To become overly ambitious or greedy.

(colloquial) To start behaving properly; get one's act together.

Alternative form of break a butterfly upon the wheel

Alternative form of break a butterfly upon the wheel

Eristalis anthophorina, a species of dronefly.

(colloquial) Expresses skepticism toward a hypothetical argument by another.