So- I have a Black Australorp hen who has gone broody... she has not left the nest box for at least 3 days! I would like to set eggs under her and try to hatch some, but I'm not sure how many to set or what to look for in an egg to try to hatch. Is there a way to tell if they are fertile without cracking them open? I have 3 very zealous roosters! And I know I've gotten some fertile eggs in the past. Or is it just kind of a crap shoot? Put some under and wait and see? Thanks for the help!