Hello We found some mallard duck eggs a month ago that were abondaned so we bought an incubator for them. It's now day 29 and 4 out of the 7 eggs ( which i think are all fertile as I candled them just before lockdown) have shown signs of external pipping. There is one that is more along than the others and has made a small hole through the membrane unlike the others, however it's been over 24 hours now and it hasn't made a lot more progress. It was chirping and sticking its beak out so we know it is definitely still alive but we aren't sure whether it is normal for it to take this long to hatch and whether or not I should assist. Any advice would be much appreciated as I have never hatched eggs before! Thanks!