First, the egg needs to be fertilized. This means you need a rooster. Hatching eggs need to be fresh, unrefrigerated, and unwashed. Naturally clean eggs are a better option so make sure you keep your coop clean, particularly the nesting boxes. Do not clean eggs that you plan to hatch; if they're excessively dirty, don't use them. If you collect eggs immediately, the eggs are usually clean. Eggs should be handled by humans as little as possible. While you can buy hatching eggs that come in the mail, it's better to choose fertilized eggs from your own chickens; they'll be more likely to hatch.