There is a bridge over a valley in Rosedale Road, Gordon, in the North Shore area of Sydney. Every summer night, as the sun goes down, thousands of flying foxes fly out of the valley and wing their way to their feeding grounds. They eat fruit, and feed all night, then return to their roosts before the sun rises in the morning. It's quite an impressive sight, which goes on for about 20 minutes, as they fly overhead. 
