We have our girls in an ark-style tractor with two nests up top. The girls just started laying recently, and they're kicking all of the shavings out of the nest. The newest layer is particularly bad about it, and when she lays, the eggs are getting cracked on the wood bottom of the nest. Is there anything I can put on the bottom to prevent the eggs from cracking when they are nesting? Something better to use in the nest box? Thank you!