I have a broody cochin and a broody silkie, no rooster. I got fertilized eggs for them to sit on. The cochin was given 5, the next day there were six under her. I didn't think she would lay any more eggs. I didn't mark them at all because I thought that might harm the eggs. Another one of my hens may have gotten into the box. Neither one of them has left the box that I know of, (hopefully only for a quick drink and snack which are close by). Never done this before, is it normal?