This has been going on for about a week now. Some information on how I'm keeping them; they have water deep enough to dunk their heads in, using specialised duckling feed. Have been using pine shavings from the day i got them. They look perfectly normal otherwise (eating, drinking) just when resting two of them start whistling, i do notice them breathing abit faster too. I'll post a picture of my set-up. I posted this not in the duckling forums by accident reposting here. Any advice is appreciated.