Usually when a egg hatches on time mom eats the shell and goo so probably not that. I only put the suggestion up because last year I kept finding hollow runner eggs. One day I walked out into the barn and here was this magpie stradling the egg shell had pecked a big whole in it and sucking everything out of it. The shell was as clean as if I had blown it out. snakes just swallow the whole egg. Let me know if you figure out what did it.These are broken completely, but no residue inside. It is like the eggs hatched successfully, but some of them were definitely too early to do that.