Then, after the Sun went down, Saras Windecker and her team headed out. In the dark of night on the peninsula"s quiet suburban streets, Windecker, a research fellow at the University of Melbourne, walked slowly down the middle of the road, her headtorch shining into the surrounding trees, and started counting. She was conducting spotlighting surveys to see how many possums there are in the region. She began in the north of Melbourne, where she would find about 30 in an evening. But as she got closer to the Mornington Peninsula, "we started seeing these really high numbers – more than 100 possums in a single evening of spotlighting," she says.