We discovered how hummingbirds generate the humming sound they are known for. The hum stems from the fluctuating aerodynamic forces their wings generate to hover. The work is a collaboration of my lab with Sorama and the TU Eindhoven. We found the oscillating aerodynamic forces generated by flapping wings are primarily responsible for the wooshing, humming and buzzing sound that large birds, hummingbirds and insects make in flight. The research was published in eLife, featured by an eLife insight by Robert Niese and picked up by the worldwide media. See this video made by Dutch science documentary maker Karin Schagen. We were interviewed by the Dutch national news broadcaster (NOS 8 o’clock and NOS children’s news). Biomimetic applications include designing more pleasant-sounding fan and turbine blades.