I've been carefully watching my nest of call duck eggs and I've noticed that they (the adults) frequently leave the nest. Is this normal? The eggs feel quite cool when they've left them for up to half an hour (covered with bedding and feathers). I candled them and all but one appear to be growing and still have good veining. If they were dead, would there still be veining? Sorry for so many questions from a newbie. The next batch is definitely going in an incubator. I just don't trust these ducks lol!