I have 17 silkies hens. They are all separated by color, (splash, paint, white, black, and buff) I was getting eggs out of every pen about every other day to every couple days. For the last 6 weeks I have got one egg out of the black pen and one out of the white pen. They eat a layena/cracked corn mixture and always have plenty of water. No birds have any sign of being ill and all eat and drink fine. What could be causing this? Any replies would be helpful! Thanks!