Anything moving through air against gravity makes a sound, and the catalogue of those sounds is wider than most editors give it credit for — a butterfly's wings aren't silent up close, an eagle's primary feathers cut differently from a crow's, and a bee passing the mic at 18 inches reads as a different species than the same bee at 6. 118 flying object SFX working that whole airspace: plane pass-by with stereo doppler, birds flapping at varying body-mass, eagle and crow calls captured mid-flight, bee buzz at multiple distances, and the surprisingly audible wing-beat of larger butterflies.
Nature documentary editors pull the eagle and crow material under wide-sky shots where the sound places the bird before the lens finds it. Animation studios reach for the butterfly-wings takes because real-world subtlety reads more magical on screen than synthesised sparkle. Game ambience designers layer the bee-buzz cuts across summer biome levels. Free to grab for video and moving edits with no signup wall.