So tonight when my son and I walked into the duck pen to feed them, my son found a egg. A hole had been dug and the egg laid in the hole. Of course my son who is 3 picked the egg up. To me it looked smaller than a chicken egg, is this normal? It was kind of oblong with a grayish tint to it. We have mallards and a male and female Peking, so I'm not sure who laid the egg. We got them at the end of March so they are around 20weeks. I haven't noticed any ducks in particular spending time in the pen, so how do we know if its a fertile egg or if the mother will even sit on it? This is our first time with ducks so this is new. Thank you.