Thanks, I'll have to go and get one. Mine worked on most, but not all. And when I let her out yesterday, a couple of the others decided to go sit on the nest while she was out, they also laid eggs. Silly me, I never thought about it. Now I don't know what eggs are fertile. I have 3 or 4 extra eggs in the nest. I'll go out today and get one. Thanks for the suggestion. And I will mark the ones that are fertile. I had read about doing it, just forgot about doing it.