Behavorial Drift and Nymphing

Maine naturalist R. J. Mere does an excellent job of explaining a phenomenon called “behavioral drift,” in which nymphs intentionally release themselves into the current and spread out at key times of the day, often in the morning but particularly in the evening, two or three hours after sunset. “They crawl to the tops of these rocks and stones and allow the currents of the river to take them away. They drift for a few yards and then cling to a new rock

and crawl to its underside and make it their new home.” In the York County Coast Star.