My chickens [I have 19 of them ]have not been laying many eggs for a while now. we have had 2 eggs in 3 days. We were getting more in the winter. I live in western PA where it has been very warm over past 2 weeks. Is it the abrupt change to weather?? Please help me to understand why. 11 of the hens are 2 years old and 8 are 1 year old.