An island is a unique place, each one host to an ecosystem like on other on Earth. So when a mammal like a rat does arrive, it sends the ecosystem into chaos. Such was the situation on Seymour Norte.

The answer for it was drones-big ones. Weighing 55 pounds, the six-rotor robots carry 44-pound payloads of specially designed rodenticide pellets. Those are colored blue, which research shows doesn't attract the attention of birds. Working from a boat offshore, operators manually launch and land the drones, but let them fly a predetermined bombing run on their own.

A helicopter could also perform this kind of mass elimination. But Seymour Norter is less than a single square mile. That requires precision. "We don't want to put bait where rats dont exist. We don't have any interest at all in seeing bait go in the water or ponds," syas Chad Hanson, project director for Island Conservation.

And that precision is working-the team says the rats are nearing elimation. Now Island Conservation is thinking about other places that might benefit from such drone. "You can take a drone and pack it up and put it on a plane and you can go anywhere in the world with it," Hanson says. A helicopter, by contrast, is nowhere near as portable nor as cheap to deploy. "That's effectively opening up a door to a whole new suite of islands that haven't been feasible in the past."