Help! My duckling has balding spots

[NewMotherDuck7]

I am new to raising ducks and my duckling Howard has bald spots, not bloody or anything but looking red and sort of irritated. My other duck Darkwing picks at Howard but I'm not sure if it is because of that or if he is allergic to something. I put newspaper in their cage last night to help with water mess but they keep pecking at it so I'm leaving it out when I change their bedding today. Also would adding brewers yeast to their food help with any issues? Benefits of it? Thanks so much! Im a very worried new mommy so any information or advice is helpful

 

[HennyPenny2]

I hope this link works but Amiga gave me some info about a bald spot on one of my ducklings (although mine doesn't sound like yours) that I thought may be helpful till someone else can give you more help.
https://www.backyardchickens.com/t/1096044/bald-spot-on-ducklings-head#post_16846610