One of my three five week old ducklings keeps opening and closing their mouth. They'll yawn now and then between those times, too. Like every 3 seconds, it opens it's mouth, closes it. Thinking it was choking or dehydrated, I picked them up and took them to their water, but it refused to eat or drink. Even with the others around, it wouldn't eat or drink with them. I'm really worried about them, it's a crested magpie or ancona (unable to identify which) not sure what gender and it just turned 5 weeks old. Help?