Callis are thick now. Hatch starts late, about 10:30. By 11:30 clouds of them are dancing above the water. If you can find the fish, they are eating the nymphs like crazy, but no adults. Size 14 light tan mayfly nymphs are the ticket, no weight. During the frenzy, they are also eating other mayfly patterns, like PTs, or olive nymphs. We had to leave the lake yesterday at 12:40, but the fish were still gorging themselves at that time - tough call! Good luck . . . .