We have 6 cochin feather feet chickens in a large coop. One bird has been broody and sitting on unfertilized eggs for about 2 weeks. She had hatched out chicks in the past so she knows the drill. We just ordered 25 more cochin chicks (we only want about 6 but the minimum was 25. we have other homes as they grow) and we are getting 4 runner duck chicks. The idea is to take the mom on the dud eggs and and switch out the eggs for chicks. The number will be a challenge but lets say that isn't an issue and the mom takes care of everyone nicely, will the baby runners be accepted just the same or will mom know and not want to care for them?