Nor have I ever noticed that the moon has any influence on when ewe will breed or lamb. Same with the weather. While I like to complain that they wait unto the coldest, windiest, blizzardiest night of the year, in reality, it's pretty evenly spread between warm and dry and cold and wet. Ewes will births when their lambs are full baked, sometime between 144 and 156 days. 146-147 has been my average. You will not see a change of behavior in the ewes, such as secluding herself, until she is actually in labor. They do that hours in advance of lambing, not days.