Rat Island No More
Rat Island, part of the Aleutians in Alaska, had been infested with rats since a Japanese ship wrecked there in the 1700s. It is now rat free after a mass poisoning campaign proved successful. The project did have a few glitches, however, including the death of 43 Bald Eagles. The sacrifice seems well worth it if seabirds start breeding on the island in numbers like they do on other, nearby, rat-free islands.