I believe getting mine to take this was the most difficult part of having ducklings, for me. No matter what I put it on, they had absolutely no interest at all. My ducks haven't ever liked many treats at all, with the exception of mealworms and occasional scratch, but I wouldn't give scratch to ducklings. I ended up having to get mealworms that weren't dried, but they weren't alive either. I believe it was a "Flock Party" brand treat. I would inject the B complex into one mealworm at a time. This was very time consuming and wasteful, so I wouldn't advise it unless it was the last resort. I really just wanted to reply to let you know that you certainly aren't the only one that experienced this. It really stressed me a lot and in turn, I believe the ducklings picked up on that. I am so happy that you noticed this so quickly and your acting on it before problems arise. You've certainly got some lucky ducks to be with someone so attentive to their needs! Best wishes to you and your flock