Okay, for the record, these guys are loud and they begin singing at sunset. A chorus of humming, in perfect rhythm an unison. The ultimate white noise of the jungle.  But they are invasive, and as such are causing a lot of damage to insect populations, which in turn impacts bird population, other insect consuming populations (like the good spiders) and soil quality.

The Coquí  is a Tree Frog (Eleutherodactylus coqui).  The species is named for the loud call the males make at night. This sound serves two purposes. “CO” serves to repel males and establish territory while the “KEE” serves to attract females- a kind of war cry and love song in one.  The auditory systems of males and females respond  to different notes of the male call.