[davidmw]

I have an indian runner duck which currently is laying 1 egg per day which are possibly fertile and am hoping that she might start to sit on the eggs at some stage.   
 

[Rhiannon]

I dont know about ducks but chickens wont budge after they have laid an egg if broody, normaly you can reach under a hen to retrieve eggs if thier not broody but if broody they will peck at you and they sit in a different way, its more flattened , plus of course they wont budge .

Only experience here is a Bantam so im not exactly an expert lol Im sure some one with more knowledge will come along soon

[Sassy]

I don't know! But ducks are not reknowned mothers and even if they start to sit often then get fed up and leave the nest. Most people use and incubator or a broody hen.