This is a Skywalker Sound sound effect that was created by Gary Rydstrom. It's first usage was in the Disney and Pixar animated film, A Bug's Life (1998). The sound was used for the Mosquito's that are shown throughout the film whenever they fly around, as the sound effect is listed here. Links: https://soundeffects.fandom.com/wiki/SKYWALKER_MOSQUITO_BUZZING_SOUND#Audio_Samples