Duckling not repelling water

[KTee]

I have some ducklings that are about 2 weeks old. When they go in the water, this 1 duckling doesn't repel the water like my other ducklings do. It doesn't stay fluffy and when they come out of the water, it is actually wet. The water doesn't run off it, like it does on my other ducklings. Any ideas why this one doesn't seem to repel water and what I can do to help? These ducklings are my students pride and joy since we hatched them in our classroom. They are very attached and I want to ensure I'm as knowledgeable as I need to be to care for our ducklings since this is my first time hatching ducklings.

 

[sloanbychoice]

Are they all the same breed?
I’m really new to ducks, but I thought they didn’t repel water until much later anyway. I believe they don’t oil up until they have feathers in.
Hopefully, someone more knowledgeable will chime in.