Gnats, a common term for various small flying insects like fungus gnats, drain flies, and non-biting midges, technically produce sound. Like all flying insects, they create vibrations in the air by flapping their wings, which translates into acoustic energy. Although the scientific answer to “Do gnats make noise?” is yes, the volume is usually too low for the human ear to perceive. These tiny flies generate sound through mechanical movement determined by the physics of their flight.
The Physics of Gnat Sound Production
The sound produced by a gnat is a direct consequence of its wings oscillating rapidly through the air. This mechanical movement generates a pressure wave, which is heard as a tonal hum or buzz. The fundamental frequency of this sound, which determines its pitch, is directly linked to the insect’s wing beat frequency (WBF).
Because gnats are small, they must beat their wings at extremely high rates to generate enough lift to stay airborne. Smaller insects require disproportionately higher WBFs than larger ones. The tiniest gnats and midges can have WBFs ranging from 650 to over 1000 beats per second (Hz). This rapid oscillation produces a very high-pitched sound, primarily a dipole tone resulting from fluctuating aerodynamic forces.
Audibility: Why Gnat Sounds Go Unheard
Although the frequency of a gnat’s wing beat may be quite high, the amplitude, or loudness, of the resulting sound is very low. Sound intensity is measured in decibels (dB), and the absolute threshold of human hearing is approximately 0 dB. A gnat’s flight sound is far below this threshold, especially at a distance of more than a few inches.
The sound energy created by a small insect dissipates quickly as it travels away from the source. The gnat’s high-frequency, low-amplitude sound wave is easily masked by ambient noise, such as a refrigerator hum or rustling clothing. While the human ear detects frequencies between 20 Hz and 20,000 Hz, our hearing is most sensitive between 2,000 and 5,000 Hz, meaning the gnat’s high-pitched sound is not readily detected.
Misidentification: Other Small Flying Insects
The common perception that gnats buzz often results from misidentification, as the term “gnat” is used loosely for many small flying pests. Larger insects, such as mosquitoes or houseflies, produce a more clearly audible noise. For example, a housefly’s WBF is typically around 200 Hz, generating a louder, lower-pitched buzz than a gnat’s sound.
Mosquitoes, while small, generate a distinct and noticeable wing tone used for communication, particularly in finding mates. The female mosquito’s WBF creates a specific frequency that the male detects. Therefore, a clear, high-pitched buzz near the ear is likely a mosquito or another slightly larger fly, not one of the nearly silent gnats.