I I am new at the ducks raising. Kids raised 15 ducks in spring. We let them free range during the day. Pen them up at night. They have been mating for about one month. Have never seen a eggs. In last 3 days 3 females are gone. 1 on 1day and2 yesterday. There is no sign of any struggle. Would the females wonder off to find a nest or do I have a predator problem in broad daylight. Help only 4 females left.