I've had my little N. Oerstedii for well over a year and a half. Usually he comes out when I'm down there, and just looks around. Last week I had company and my friend put her hand on the glass. He bolted out and literally tried to get her. It was pretty cool, unfortunately I didn't have my camera, but it was the best I've ever got to see his underside. She moved her hand across the tank and he stayed right with her. Now I'm assuming it was all the shiny jewlery she had on?