KAILUA, KONA, Hawai'i — It's unlikely the Big Island and Maui will ever be completely free of the annoying chirps of coqui frogs, according to the head of the state Land Board.

The Big Island is the most heavily infested with the invasive frogs whose noisy shrieks keep residents up at night, followed by Maui.

But the infestations there are probably too far along to completely get rid of the frogs, said Peter Young, who is also the director of the state Department of Land and Natural Resources.

"It's early enough on Kaua'i and O'ahu so that eradication might be possible," Young said Thursday. "On Maui, we're probably talking control, and on the Big Island we need to do a lot more work because the frogs are getting into very isolated areas."

Coqui frogs are beloved in their native Puerto Rico, but they're reviled in Hawai'i for their loud shrieking.

With no natural predators, such as snakes, to keep coqui numbers under control, the frogs and their loud "ko-KEE" mating calls have multiplied exponentially.

Hawai'i's year-round temperate weather and open space also provide the coqui with an ideal environment in which to reproduce. The first frog — or frogs — are believed to have hitched a ride to Hawai'i in a plant shipped from Puerto Rico or Florida in the 1990s.

Young said the state has issued a request for proposals from those seeking funding research for coqui control.

He said he hopes scientists will take advantage of money being offered by the state to come up with a way to control or eradicate the pests.

Many residents on the Big Island and Maui are using hydrated lime as an effective means of chemical control.

However, Young urges people to work with the Big Island Invasive Species Council before trying to control populations near their homes. The council could advise residents on the best means of control and loans of spraying equipment, he said.