Why are these little guys in so much trouble? It's for their excessive chirping sounds. Only the males sing, but they begin at dusk and will keep up the cacophony until the sun begins to rise. In larger populations, they are reported to be as loud as jet engines. They're now considered an invasive species and steps are under way for eradication. If populations continue to grow, they can eventually affect tourism. Even now, some florists and commercial greenhouses are prohibited from exporting off the islands for fear the little coqui will spread elsewhere.
Only two species are reported to have the biggest lung power: the mountain coqui and the common coqui. Evidently these are also the most adventurous, hitching a ride to Hawaii in the 1990s. With no real predators to control population growth, they've continued to thrive while finding ways to migrate to more populated areas. Coquis also mate during the wet season and that's another reason they've gained such a stronghold in parts of Hawaii and especially in greenhouses. Also, local experts fear that they'll consume insects that native birds thrive on, which could impact established native species.
While these little guys are just downright cute, they're not quite so charming when they're disturbing the peace all night long.