I have two cochin hens sitting on nests on the ground in the coop. They are too big to get in the nest boxes and have always laid their eggs on the ground. I really, really want to experience them hatching some chicks but the eggs keep disappearing. I'm assuming since there are no shells around that something is swallowing them whole. Would snakes go under a hen to get the eggs? I know it happens during the day when I am gone. How can I protect these hens' eggs? thanks!