So we got one egg the day before from one of our nine 20wk Australorps. However, the egg was cracked since the hen dug out the wood shavings on the nesting box and laid the egg straight onto the wood. We then put a bigger lip on the nesting box and replaced it with straw (figuring it would be harder to dig out than wood shavings) and today the middle part was bare wood again. No egg though but I figure they're kind of on their way (I see squatting and just a general interest in the nesting boxes). How do you prevent them from preparing their nest in such a manner?