JOEL SARTORE, NATIONAL GEOGRAPHIC PHOTO ARK/National Geographic Creative

This giant Australian insect is still alive, despite being declared extinct nearly a century ago

Sometimes they come back. Once declared extinct, Lord Howe Island stick insects (Dryococelus australis) are actually alive and well, according to a new study. The 15-centimeter-long, plant-eating insects, also known as tree lobsters, once thrived on the lush vegetation of Lord Howe Island, between Australia and New Zealand. But after a ship accidentally introduced black rats to the island about a century ago, the stick insect population plummeted. In 1920, they were declared extinct, only to be found more than 40 years later on Ball’s Pyramid, a volcanic sea stack about 20 kilometers away. But these critters didn’t look identical to old stick insect museum specimens, leaving scientists wondering whether they were the same species. After comparing their DNA, researchers now have found a difference of less than 1%, well within the range expected for two individuals of the same species, the team reports today in Current Biology. The finding suggests that the giant bugs could be successfully reintroduced to Lord Howe Island, the scientists say.