I only have 1 experience with this. I think it depends on your hen. If she's the type that will leave the chicks once they are born it might not. But I had 4 eggs. 2 I left under the Hen and 2 I incubated. I wasn't sure she would be a good broody since this was her first time. Mine hatched on day 20 and hers on day 21. I kept mine in a day or two and when she was out with her 2 chicks showing them how to eat I brought them out and showed her them and put them by the other chicks. At first the 2 chicks I hatched followed me bc they were used to my voice. I ended up putting them all in the coop and shutting it until she accepted them which took a few hours. But I have read putting them under her from behind when they are a day old is best. I think I brought them to her a little late but it still worked