Hello, I'm sorry if this is a bit vague, but I'm trying to find reasons on why I found my Welsh Harlequin dead tonight in her run. I have(or had) four ducks, all currently 6 1/2 weeks old. I have a small closed coop for them with a fenced run. I keep food and water in the coop at all times(currently on Nutrena Chick Grower Non-Med, plan to switch to less protein at 7-8 weeks) and a kiddie pool out in their run. For the kiddie pool I have a big rock inside to give them a step up and all around the outside we have built up wood chips(really big chunks) to allow them to walk into the pool. I change the water every few days, but can they get toxic from drinking the water if it's not clear? The only treats they get are handfuls of red kale and blueberries(only a couple times a week). I'll admit, I took a nap and woke up late, after dark. When I went to put them in for the night, the other 3 were already in their coop drinking and she was dead out in the run by the pool. She was laying stretched out on her stomach with no visable signs of any wounds. No blood, no discharge anywhere. Eyes and vent area looked clear. Nothing looked broken. I had just checked on them 4-5 hours earlier and she acted completely normal. My father posed the suggestion that maybe she choked on something and now I'm paranoid that maybe she attempted to eat a smaller wood chip and got impacted? I do work at a vets office and I'm considering asking if they'd be willing to cut her open and see. I hate to have to do that, but I'd like to know what is going on for the sake of my other ducks. I'm so new to this and I feel so stressed out. This could have been my fault. I plan on raking up all of he wood chips tomorrow just in case, but I need to figure out a method for them to get in and out of the pool safely. Any suggestions?