I had some duck eggs in my bator,and they were over due and I could not never hear them peep in shell. Don`t know what happened.And mother in law cooked some and she said her eggs was stuck so bad,she thought she would never get them peeled.And have not been giving oyster shells.So I come home and finally decided to try to get them out.They had wiggled and rocked.But could not get out.So their beaks was stuck to the inside of the lining of the shell.And I lost all 5 of them. They were at full maturity. Never peeped inside of the shell or piped.Don`t know what happened.Help!!!! If anyone might know what could have happened info would help.Thanks Sandra Mystery!!!!