My duckling is very lethargic and his sibling is perfectly fine

[Vanessa drawdy]

I have two baby ducks a Pekin and a mallard my mallard is imprinted on me but the Pekin isn't today my mallard is very weak and lethargic I gave him a little acv in their water and they both ate this morning im worried that he's to stressed from being away from me is there anything I can do other than letting him sleep in my hand right now that I can do this is my first time ever having ducks and they are both like my babies I need help please..

 

[FrostHollow]

How old is your duckling? I understand that it is imprinted upon you, but they should be equally as bonded to the other duckling housed with it. Ducklings require warmth. It's possible that this baby is too cold and possibly dehydrated so you may consider putting it under a lamp and offering it water. Maybe try a little sugar water to help give it a boost. What are its droppings like?

 

[BelovedBirds]

I have two baby ducks a Pekin and a mallard my mallard is imprinted on me but the Pekin isn't today my mallard is very weak and lethargic I gave him a little acv in their water and they both ate this morning im worried that he's to stressed from being away from me is there anything I can do other than letting him sleep in my hand right now that I can do this is my first time ever having ducks and they are both like my babies I need help please..

How old are they? What food are they on?
Can you describe how you mean "weak"? Is he walking, drinking?