Delima. I had 2 mallard duck eggs in the incubator yesterday was the 28th day. One hatched on day 27 how long do I wait on the other one before I give up on waiting for it to hatch. I candled them both before lock down and they definetly had duck's in them? What is the longest it could take to hatch? My kids keep looking for it to be pipped or to hear it and so far nothing. Please some advice!