They were Dryococelus australis. A search the next morning, and two years later, concluded these are the only ones on Ball's Pyramid, the last ones. They live there, and, as best we know, nowhere else.

How they got there is a mystery. Maybe they hitchhiked on birds, or traveled with fishermen, and how they survived for so long on just a single patch of plants, nobody knows either. The important thing, the scientists thought, was to get a few of these insects protected and into a breeding program.

That wasn't so easy. The Australian government didn't know if the animals on Ball's Pyramid could or should be moved. There were meetings, studies, two years passed, and finally officials agreed to allow four animals to be retrieved. Just four.

Source: http://www.npr.org/sections/krulwich/201...