Watch out for a sheep separating herself from the rest, sudden small, sharp movements, nabbing at side fleece or a foot, damp looking patches on the fleece (especially across the shoulders), and lots off lies settling on or buzzing around one sheep in preference to the others. Also check feet are sound as flies will lay in clees with footrot. We don't put anything on the fleece coming up to shearing and do the lambs with Clik once we see more than half-a-dozen greenbottles in a day. We put the mature sheep on the windiest fields if we can.