The Bogong moths are back — blanketing backyards across southeastern Australia

Steve Whan stepped outside in the New South Wales alpine country this weekend and found the night had come with wings. Bogong moths — thumb-sized migrants with a wingspan up to 5cm — have been in steep decline for years, thinning their spectacular 3,000km (1,900-mile) spring migration to the Australian Alps. But this year swarms are showing up in backyards and homes along the east coast, including Sydney. "It's really exciting to see this recovering population coming our way," said Whan. Victoria's Chief Biodiversity Officer James Todd called the surge "a positive sign for biodiversity." The harmless, legally protected moths feed the endangered pygmy-possum and pollinate eucalyptus trees. Scientists think heavier rains in northern NSW gave the moths' larvae extra food.