Actress Liv Tyler says she and her father Steve Tyler have a family "bird-call" they make to help find each other in crowded places.
"It's a super New York thing. Kids who grow up in certain neighbourhoods have a call so they can communicate with their gang. We learnt it off friends who grew up in the projects. If you're a few blocks away and you hear the call then you immediately turn round," Liv told thetimes.co.uk.
She shared her father has one too.
"His is really funny. It's good to have your family call. It's the only way to get anybody's attention," she said.