I have suffered some losses, down to 4 hens, and one drake who is too feeble to mate them, he gets to the food and water and that’s about it. I responded to an ad for 1.5 months old runners, I should be able to sex them by voice, but how about mixing them in with the rest? Do you think I would get away with it at this stage? I was looking for some that were a bit older.