Moldy membrane

[The_crazy_chicken_girl]

Hello, I am wondering what the cause is for egg membrane to go moldy? I have 4 healthy chicks and the rest of the eggs was either moldy or not forming

 

[MGG]

Hello, I am wondering what the cause is for egg membrane to go moldy? I have 4 healthy chicks and the rest of the eggs was either moldy or not forming

Do you have a pic? I can't imagine it was mold.