I have 11 duck eggs (both indian runner and call duck) sitting ready to go into the incubator. However this will not fill the incubator. The ducks are continueing to lay each day and so i was going to wait until i had enough eggs to fill the incubator before turning it on. Although i have heard that after 7 days something happens to the air cell meaning that there is an unlikely chance of the bird hatching. Also i have heard that eggs cannot be added as the humidity is efffected. Could someone please advise me on what to do and how long eggs can sit before being incubated. Many many thanks!!!