Finches in the Galapagos Islands, best known for inspiring Charles Darwin's theory of evolution by natural selection, are in danger from a blood-sucking parasite.

According to Reuters, scientists are working on a solution to preserve the endangered birds by targeting the larvae of the parasitic insects that find their way into the finches' nests.

The scientists placed cotton balls laced with a mild pesticide in areas where the finches build their nests. When the birds pick up bits of the cotton, they are actually building their nests with a chemical that will kill the parasitic flies that are slowly killing off their young.

The researchers, whose study is published in the journal Current Biology, are even more excited to say the pesticide poses no threat to the birds or their offspring.

"This parasite is not historically found in the Galapagos Islands and, therefore, Darwin's finches have not had enough time to evolve defenses against the parasites," study co-author Dale Clayton, University of Utah biology professor, told Reuters. "In some years, 100 percent of nestlings die as a direct result of the parasites. It is critical to find a way to control the parasites in order to help the birds."

Controlling these parasites has been a priority since they first appeared in 1997, most likely arriving at the Galapagos aboard planes and ships. Study lead author Sarah Knutie, a biology doctoral student at the University of Utah, said the inspiration for the pesticide cotton balls struck quickly.

"In 2010, I was sitting on my porch at the Charles Darwin Research Station and noticed Darwin's finches continuously landing on our laundry line," Knutie told Reuters. "The birds were pulling frayed cotton fibers from the line and presumably taking them back to incorporate into their nests."

After their experiment, 19 of 20 nests with pesticide cotton balls incorporated in their nests were parasite-free.

"Novel parasites and diseases are an increasing threat to our environment," Knutie said in a press release. "Many animals cannot defend themselves against such parasites. Therefore, the animals need our help in developing effective ways to protect them. Our method of self-fumigation is a simple and immediate solution that can help Darwin's finches combat this devastating parasite."