Depends on the species. Some can hatch in as little as three weeks, others may take another couple of weeks. Mallards usually hatch between 26 - 30 days. Weather can be a factor, too. They leave the...
Incubation PeriodHatching PeriodDays 1 through 25Days 26 through 28Temperature99.5° Farenheit98.5° FarenheitHumidity86%94%Turns Per Day3, 5, or 7Stop Turning
The egg, when held to the inside of the wrist should feel warm. Human body temp. is 98.6F and the duck egg is supposed to be incubated at approximately 101F.