• Like many islands around the world, Tetiaroa Atoll in French Polynesia has been overrun by rats and other invasive species that profoundly affect its terrestrial and marine ecosystems.
• In July, the paradisiacal 12-island atoll was declared rat-free after years of concerted efforts to wipe out the predators.
• Scientists have been studying the atoll’s plants, seabirds, insects, lizards, crabs, coral and algae, establishing a uniquely comprehensive ecological baseline to better understand how the rat eradication will affect the atoll — and others like it.

The black-and-white motion-triggered video looks like an outtake from a cheap horror movie: A handful of rats circle a smooth, platter-sized mound of sand. Suddenly a sea turtle hatchling appears, digging out of the nest. A rat grabs it by its head and quickly drags it off-camera. A second hatchling is snatched by another rat, flipped on its back and dragged off. The video ends.

But there’s more. In 2007 the first yellow crazy ants (Anoplolepis gracilipes) were identified on one of the same islands, or motus, of Tetiaroa Atoll in French Polynesia. There are some 200 species of ants in Polynesia, all nonnative, but the yellow crazies are the worst. “They spray formic acid that can blind or else deform the wings and legs of seabirds,” says Jayna DeVore, one of the scientists working out of the Tetiaroa Society’s eco-station on the main resort island of Onetahi. “I’ve seen chicks dancing in their nests to get the ants off them.”

Read more of David Helvarg’s article in Monga Bay.