I read an article in Backyard Poultry magazine by Harvey Ussery about letting your chickens process your compost for you. I am thinking about letting my chickens have access to my compost, but worry about the large number of egg shells it contains. We usually don't crush them up or anything before we throw them in. I don't want the hens to start eating their own eggs , so I need to be sure they don't link the compost ones with the ones they lay. My question is, how much do I need to crush them up to be safe. I really don't want to be keeping the shells in the house waiting for them to dry out, nor do I want to be toasting them in the oven all of the time. Would just hand- crushing them right after they are used work?