We had two chicks recently raised by two hens in a flock of 20 hens and a rooster. At about 2.5 weeks one mother forgot she'd ever had babies and at 3 weeks the second hen did the same. The chicks ran after the second mother for a day or so but after that they were on their own. A week later the chicks were roosting with the aunties, no problem. This was about 4 weeks earlier than we usually integrate chicks when we brood in the house, but then we aren't out there to protect them. We have three feeders and three water buckets.