I just sighned on yesterday and feel a little overwhelmed with all of the information I have found here so far. I have had chickens much of my life and now wish to go a step further. Incubating and raisnig them. Have either purchased day old chicks or started with older pullets. This is my first time out with the incubator so I just have been reading and asking questions. I candled my eggs yesterday and so far all but 3-4 are doing something. I have a small variety of birds and was wondering at what point can I change roosters and know that the eggs are his vs the current rooster? A few days or weeks? Not versed in the egg laying process. At what point does fertilization take place? Any info would be greatly appreciated! Thanks in advance Ang