Week old duck, is this normal?

[nive]

I gave a mallard duckling that's about 6 days old.
It makes a slight crackaling noise when it breaths. It's done it for the whole 6 days I've had it, is it normal?

It dose a little yawn now and then and a few little sneezes but not often. It's breathing seems normal.Drinking and eating well.poos look normal.
Today it's been sleeping with one leg stuck out behind it, like it's stretched it's leg and forgot to pull it back in.

 

[Kevin565]

How deep is the ducklings waterer?

 

[nive]

It can get its whole head in there so it's able to clean out its nostrils. It also has access to a big tub of water to swim in twice a day.