I am new with ducks , and made the mistake to get 10 ducklings all at once , All of the ducklings are straight run Pekins that I got from a year around selling website. The ducklings are around 3-4 weeks old and should be getting their water oils and white feathers soon. I keep the ducks at my friends farm since I live in town and visit them around 3 times a week , I've been noticing that they are some that open their beaks like their going to make a noise but it just comes out as a little breath I'm keeping them in a warm area with a heat lamp but it is winter and I'm concerned. They also make some almost quick noise that sounds like a chuff for some reason , I don't think they are sick but they might be sneezing, I don't know , like I said this is my first time with dealing with such a messy animals that can get sick easily , plz help ?!