I got 2 new chickens recently. They are of laying age. Between the 3 chickens I have, there are 2 nesting boxes, so the ladies aren't cramped for laying space. I've found eggs twice in the nesting box. But I keep finding cracked eggs under their perch. So I'm guessing one of them is dropping eggs at night. Is that something that happens? What can I do about it? Today I found the egg whites alone, as it looks like they ate the shell and yolk for the first time. I need to break this habit! Advice?