My duckling is about a week old. He is balding behind his wing and in front of his leg. He seems to itch at those two spots a lot and both spots are red.
Less heat and drier Brooder. Lots of ideas on dry Ducklings. Only heat where they sleep and cooler over feed and water.
Maybe try raising your heat some that's a might warm for ducklings 80 -82 in one corner and maybe 5 degrees cooler over where you keep feed and water. Can you show us your set up? and also letting your ducklings have some warm water swims can help with itchiness. Just make sure they start out with water just up to top of legs so the can stand up and it's nice an warm water and where your giving them a swim. Then let them dry under their heat lamp. They'll start to preen and get the oil gland working.