system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What makes a fly “buzz”?
gpt
Our sense of sound works by collecting vibrations with our ear drums. In most situations, these vibrations ripple through the air.

The "buzzing" of an insect is caused by their wings flapping and vibrating the air around them. This rapid vibration is collected by our ears and interpreted as sounds. Smaller insects (mosquitos) have smaller wings that flap faster, causing more high pitched noises. Larger insects (bumble bees) with larger wings do not need to flap so frequently so they buzz with a lower pitch.

Besides insects, humming birds flap their wings fast enough that we can hear it as a low pitch. However, regular birds flap slowly enough that they cannot vibrate the air quickly enough for our ears to interpret them as sounds.