I just went through an egg eating incident. I could tell because all signs of the egg were gone except for the mess left on other eggs and on the shavings. Even with just a broken egg I usually find some of the shell. Also,the egg mess was always in one nest and happened daily. Too much coincidence for just an accident. I blew out an egg and filed it with blue food coloring and identified the culprit that way. I trimmed her top beak,hoping that would discourage her but as soon as it grew out,she was back at it again.I caught her(marked her with blue coloring,too) and she went into the pot.