Do my ducks not understand how to eat?

[Karmy]

I don't understand, I got them an automatic feeder and they walk right by it. the only time they eat from it is when I get them a new type of food, then after a day, they forget it exists and don't eat from it. Its not that their not hungry because when they do eat, they eat a lot. The only other time they eat is if I am throwing the food to them and they don't even both eat it, only one does and the other one just sits there and watches me throw the food. Every time I see a picture of other peoples ducks they eat just fine, I don't know what the deal is, any suggestions?