I have two pens of Coturnix Quail, 4 birds in each pen. The pens are physically connected, but separated by plywood. Last night all was well, but this morning around 8:00am I found all my birds dead. No wounds, no bite marks...just dead----all 8 birds. I am at a loss to explain this. Perhaps its a disease, but this seems unlikely since it occurred in two different pens and killed all the birds within a single night. I keep the pen on the back closed-in porch, so no large animal could have gotten in and scared them. Any ideas what could have happened?