Sounds like the start of a niacin deficiency. Get some niacin to supplement. You should see a behavior improvement within a few daysAlso, if anyone has any ideas as to why Mystery Duckling is always lying down? It's eating and drinking just fine but when it's in the brooder it takes a few steps then plops down? Outside the brooder and splash time it moves around just fine. Flaps its wings and preens and chases the other duckling around. Is it just a lazy duckling during down time?