The little fluffy looks alert. I haven't had one make a noise like that. As @KathiQuacks suggested, be sure the ducklings have access to water deep enough to dunk their whole heads. I see there is at least one chick in there. water tubs for ducklings are different than those for chicks. I lidded tub with a hole cut large enough for a duckling head but not large enough for a chick to get inside is what is needed.
You will probably get away with not using a heat lamp. I, just today, rescued 2 little Pekin ducklings that appear to be only 2 weeks old. One has no feathers and the other just has the suggestion of tail feathers. They were seen in gardens on one road two days ago and then appeared in gardens on the next road over yesterday. They were taken in to a rear porch last night, but the night before they were out on their own with a low of 68F. The two are now sleeping in a small dog crate in my duck house. If I had raised them myself, they would still be in a brooder in the house with the heat lamp (my house is air conditioner during the day). But as they have been outside for at least 2 nights, I think it is warm enough in the duck house for them. And they are a week younger than yours. Your 4 will snuggle up close together to keep warn
Our temperatures have plummeted, particularly at night and so I have had to bring g my 2 new du cc klings into the house. They came in last night and slept in a pet carrier. But it's not warm enough for them to go out today. I am setting up the brooder in the bath until the weathercwarms up again or they are old enoughbto brave the temperature outside!
