I have 5 barred rocks, 5 black australorps and 5 buff orpingtons who are around 18 months old. They have been laying consistently since November 2010. Their eggs have all been close to the same size since then, except for the last week. They are SMALLER. Hmmmm. The only thing that has been different is the weather. It has been really hot and humid. I've made sure they have plenty of water, good ventilation of the coop, access to the shaded run and lots of cold fruit and veggies. They get out to free range every evening for a few hours, and have access to plenty of food (crumbles & BOSS). While their production has slowed down from time to time, I've never seen smaller eggs..... any ideas?