I have a muscovy (rescued) that started laying a few months after I got her. She had been laying consistently for about a month, but had stopped laying in the nest. So I marked an egg and left it in her box so she wouldn't lay under the house where I can't reach them anymore. She was laying there for a few days and then stopped laying and is now just sitting on that one egg endlessly. I can't find any eggs anywhere else, so I'm wondering, if she thinks this one is fertilised if she would stop laying?