DH swears one of our ducklings are sick. We have 2 ducklings and 4 chicks from TSC. We get them a week and a half ago. One duckling keeps opening and closing it's bill. Randomly and not constant. DH says it looks weaker. During tub time today it's poop floated. It has never done that. Brooder is at 85-90, pine shaving on floor, eating non medicated starter, grit provided. Seems to be eating ok and drinking. Water gets changed 3-4 times a day. It does seem a bit weaker than the other. Any suggestions? I have seen some info on niacin deficiency and we are in VA and had that pretty good storm. Going to try to get some Brewers yeast tomorrow. Really want to prevent it from getting worse.