So, my girls have just started laying in the past month. They are 20-22 weeks old, mostly red sex links and a couple of mixed breeds. I was getting 6-8 eggs per day from 9 girls who were "of age". In the past few days it has dropped to 6, then 4 and then 3 today. I can't see any obvious reason why. What should I be looking for as the cause? TIA!