Imagine the sound a mosquito makes when it flies near your ear; it's quite distinct. I'm sure it's possible to distinguish mosquitos based on that (which is a factor related to the doppler signature mentioned).

I wonder how distinct it is, really. It sticks out to us, but “mosquitos is enemy #1” is one of the strongest evolutionary pressure we’ve got, right? And one of the few that persists to this day.

Our brains probably have a dedicated cluster of neurons in there somewhere specifically looking for the Mosquito noise.