Ella Davies at the BBC:
Scientists from France and Scotland recorded the aquatic animal “singing” at up to 99.2 decibels, the equivalent of listening to a loud orchestra play while sitting in the front row.
The insect makes the sound by rubbing its penis against its abdomen in a process known as “stridulation”.
Researchers say the song is a courtship display performed to attract a mate.
Micronecta scholtzi are freshwater insects measuring just 2mm that are common across Europe.
The team of biologists and engineering experts recorded the insects using specialist underwater microphones.
On average, the songs of M. scholtzi reached 78.9 decibels, comparable to a passing freight train.
More here.