Trout feed most recklessly when wind ripples mask a cast

Evidence

For the duration of a cigarette I sit on a rock midstream—and watch my trout rise under his guardian bush, while my rod and line hang drying on the alders of the sunny bank. Then—for prudence’ sake—a little longer. That pool is too smooth up there. A breeze is stirring and may shortly ruffle it for an instant, and thus make more deadly that perfect cast I shall shortly lay upon its bosom. — Aldo Leopold, A Sand County Almanac, 143