Thanks so that’s like 80F which is a little too warm they are in 3rd week of life and only need 75F then in a few days only 70F - that’s maybe why they’re doing the panting or fast breathing -
I think I heard one sneeze they just need to keep dunking their head in the water to clean out their nares . Make sure that there is always clean water That’s deep enough for them to get their whole head in. They need it to keep their eyes cleaned too.
They’re adorable
As long as they are eating drinking and pooping there is probably not any blockages . I have always used pine chips with 100s of ducklings and never had a problem with them eating them or getting them stuck in their throat or anything.
Are you giving them any treats beside their duckling starter feed?
Because if you give them anything else beside their duckling starter Feed, you have to also provide a dish of grit on the side. You can get chick grit at a Feed store or online. Don’t mix it in with their food. You just provide a dish of it. A small dish next to their food.