What type of ducks are they all? And how old are they?
Have you ever dewormed them? Worm overload *can* cause them to be skinny, j/s...
5 of them are Golden 300 Hybrids and 5 are White Layers. They turned an year old August 1st. Never dewormed. Skin and bones might have been an tad bit of an exaggeration; they're just not fat at all. Some are pretty big though, so.... Are there any other signs of worms I can look for? Could it possibly have to do with decrease in egg production?