Woke up to a dead duck

[MROO]

Please help i dont want to lose more babys

It could also have been heat stroke. How hot has it been and how much space do they have in their box at night? When you open up in the morning, is the air cooler inside, or are you hit with a wave of warmer air, like when you open up your car after it sits in the sun?

 

[PirateGirl]

If there were no signs of illness prior to the death, I would try not to worry too much about the others. As others have mentioned, a necropsy is your best bet in solving the mystery. It could have been anything, something your duck ingested, a genetic flaw (weak heart or something internal), but you are right, if it was disease, it probably wouldn't have seemed so sudden. In the mean time, double check your duck area and make sure there is nothing toxic or appealing to eat (once I had found a bunch of nails that had spilled after a project and I hadn't noticed). Also double check that their sleeping area is secure from predators. Something like a weasel can make a kill with almost no outward signs and the duck would have been too large to be removed from it's house through the tiny hole a weasel came in through. Being proactive, you will feel better knowing that you are doing all you can to protect the ducks you have left. You may never have answers, but keep taking good care of the rest and know you are doing all you can.