I got a Buff and Khaki in August, and they are the only two laying. Sometimes the eggs have the bullseye on the yolk. There has been no hanky panky going on, so I find it very weird, though I think I read somewhere that it can be up to six months????
Sounds like one of your drakes really likes them what breeds of drakes do you have, and how old are they?
I don't know about ducks but chicken hens can store sperm internally and continue to fertilize eggs for around 3 months.
