An internal-combustion engine needs four things to run. They need fuel, mixed with air, in a ratio of 14.7 to one. An ignition-spark lights the fuel and air mixture, creating combustion. Compression of the fuel and air mixture makes it explosive. The final necessity is proper timing, of the components.
1 The length of time it takes for eggs to hatch after incubation begins depends on the species and temperatures. 2  For bluebirds, it USUALLY takes about 12-14 days from the date the last egg was laid.3  Different species have different incubation periods, which can vary within a species due to temperature inside the nestbox. Depending on when incubation begins (on the last, or next to last egg), eggs in the same nest can hatch a day or several days apart. 2  It also takes a while for the bird to break through the shell. 3  It could be a new egg from a subsequent nesting if you didn't clean the box out immediately after the last fledging.
Store eggs for hatching at 55 degrees F and a relative humidity of 75 percent. Eggs stored longer than 2 weeks may decline in hatchability. If stored more than a week, turn eggs daily to prevent yolks from sticking to shells. Incubation. Muscovy ducks require 35 days of incubation; eggs of other domestic duck breeds require 28 days. A chicken hen or female duck can set on 9 to 11 duck eggs. Place the nest where it won't be disturbed during the incubation period and provide a convenient source of feed and water. The nest should be checked at hatching time.