I have a hen that went broody on me last year, and she hatched out 3 chicks. She went broody again this year, so we isolated her again and gave her 12 eggs. At about day 20, I noticed a broken egg in the nesting box and thought that perhaps a chick had hatched. I waited until day 21 to check under her and discovered that there were only 10 eggs under her and none had hatched. At day 23, there were only 6 eggs and no new chicks. I am now down to 1 egg under her and it has been 28 days. There aren't really any egg shells in there. Could she be eating them? And why? She was successful hatching eggs before.