Sorry for all the posts lately, there is so much I dont know. One of my 3 week old runner ducklings has been holding her eye closed this evening. She will open it when something startles her but then lets it close again. It doesn't look abnormal or gooey or anything. She has been eating and drinking as far as I can tell but I'm not sure if she has been as active as the others. I wiped her face off with a damp rag and gave them a water bowl to wash in but she isn't that interested in dunking her head. When should I start to worry?