I have two chickens that have stopped laying the the past week. I have also noticed yellow/white running poops under there roost. They are free frange birds and the weather here has been extremely hot (average temp for the last month is 98-100 degrees). They appear to be eating and drinking fine, although that is hard to tell because they free range. There are no attemps to spend any time in their nesting boxes. I've picked them up and neither seem to have a distended vent or tummy. I'm worried...any advice?