OK...I can use some advice because this HAS to be MY problem and not the incubator or hatcher problem..... Three hatches in a row, I have had over 20 runner duck eggs in the incubator...THREE different incubators. Throughout the incubation period, we've had VERY good luck at keeping both the temperature and humidity steady with no peaks or dips and at the prescribed numbers. We have DOUBLE thermometers and both a calibrated hygrometer and a wet bulb. BUT, during the hatching period, the runners start to hatch EARLY and then it takes 4-5 days for the eggs to hatch. This means that we have to remove ducklings and open the hatcher before the entire hatch is finished. We keep the humidity high and we spray the eggs when we have to open the top of the incubator and we HURRY to get it shut again. We try to open it as little as possible. The early ducklings hatch fast. The middle duckings hatch slower and then there is a large number of eggs who never hatch. They all candle well, but it's the hatching process that seems to be my problem. I have a friend who removes the hatchlings the minute they hatch and she opens the incubator/hatcher and sprays and doesn't have the problem. I've done things EXACTLY as she does, but I don't have her results. I am open to all suggestions, advice, information, and comments. I want to figure this out and learn in the process. We had one duckling die half-pipped tonight and the duckling after him was slightly dry in the shell, yet the humidity is right on.