I rescued an egg from a nest where a hen had hatched one chick and left the nest. I took the egg and popped it in the bator to "give it a chance." well, it just hatched and it is alone. I can try it under the hen and her one, 4 day old chick - or I could put it under a broody hen that has been sitting for 3 days. Neither is a great option but neither is raising a lone chick. Everyone weigh in, PLEASE!
