We have 3 black australorps that have been laying consistantly since the beginning of may. at the end of july, we brought in 3 new pullets (an australop and 2 barred rock) that were abour 12 weeks old then. since then, the big girls had a decrease in laying and now have stopped altogether! they are all healthy with no signs of mites or anything and appetites are GOOD (competing with the little ones for food and treats). the weather has been just as hot as all summer (we live in houston, tx) and nothing else has really seemed to change. just can't figure it out! we have looked all over the yard to see if they maybe laying somewhere other than the coop. in the last days, i have gotten ONE egg. we were consistantly getting 3 a day from them before the little girls came. any ideas??? THANKS!!!